There are a few options you can do with your old GPU, depending on its age, condition, and other factors.

Obviously, there’s always the option to simply throw it away, but it is not the most economically sound option, and not to mention not environmentally friendly.

Instead, there are more viable options you can take with your older GPUs:

• Sell it: if your used GPU is still in good working condition, selling it is a viable option. There are various forums, social media profiles, and online marketplaces dedicated to buying and selling used IT equipment and computer hardware. Selling the used GPU can help you recoup some of the initial investment you’ve made in the old GPU and also extend its lifespan.
• Donate it: another option is to donate your GPU, for example, to charities. There are many charities that accept donations of old computer hardware, and this can be a good chance for you to help someone in need and contribute back to the community. Try nonprofit organizations or educational institutions (schools) in your area, or there may be individuals near you that may benefit from your old GPU.
• Repurpose it: if your used GPU is still in good working condition, but the resale value is no longer attractive, you can repurpose the old GPU for other uses. For example, you could set up a cryptocurrency mining rig using the used GPU or set up a GPU-powered machine learning/AI development system. Setting up another gaming PC with the old GPU is also always an option.
• Recycle it: If your old GPU is no longer working, or if you don’t want to sell/donate it to others for one reason or another, then recycling it is the best way rather than letting it end up in a landfill and damage the environment. Check if there are any certified IT assets recycling companies in your area that can handle used GPU recycling in an environmentally responsible way. These secure facilities can help ensure the safe disposal of hazardous materials and the recovery of valuable components.

Selling used GPUs can be totally safe and is a viable option for those looking to dispose of their old GPUs or looking to upgrade their graphics card. 

However, it’s still important to take the necessary precautions:

• Evaluate the GPU’s condition and performance: test the old GPU thoroughly before attempting to sell it. Test whether the used GPU works as intended and whether there are any physical defects. There are various tools you can use to perform diagnostic tests on your used GPU. If there are any defects or performance issues, it’s best to be honest with the potential buyers to prevent future issues.
• Make sure it’s free from sensitive/personal information. Unlike hard drives or memory modules, GPUs do not store any personal data. So in most cases, sensitive data won't be an issue. However, if you are going to sell the old GPU as a part of a computer unit (with storage devices), make sure to remove any personal/sensitive information. Format all storage devices, and if necessary, use data erasure software to ensure your data is unrecoverable.
• Take clear photos: capture well-taken and high-quality photos of the used GPU from different angles. Use the photos to showcase its condition and don’t hide any defects. These can help potential buyers make informed decisions and can protect you as the seller in the event of disputes.
• Package the GPU securely: use plenty of packing material and a sturdy box to prevent the used GPU from being damaged during transit.
• Ship with insurance and tracking: if you need to ship your old GPU yourself, opt for shipping methods that include insurance and tracking to protect both yourself and the buyer in the event of delivery issues. 
• Sell to a trusted, reputable buyer: it’s best to only sell the old GPU to someone you can trust, or at least use a trusted platform (i.e., online marketplaces like Amazon) to mediate the transaction. You can sell the used GPU to a trusted ITAD company like Big Data Supply Inc. to reduce the potential risks in selling your used GPU.

You have several options on where you can sell your used GPUs:

1. Selling to individual buyers: for example, you may have family members or friends who may be interested in buying your used GPU. Keep in mind, however, that even if you know the buyer personally, you still need to be careful and take the necessary precautions.
2. Trade-in programs: some retailers and GPU manufacturers offer trade-in programs for used GPUs. If you are planning to upgrade your GPU, you may be able to trade in your old GPU and get a discount on the upgrade.
3. Online marketplaces: you can list your used GPUs on online marketplaces like Amazon, eBay, and Craigslist, among others. These marketplaces have a wide reach and a huge user base of potential buyers, so you can list and sell your used GPU to these buyers. 
4. Dedicated hardware marketplaces: hardware marketplaces like Newegg, Hardware Swap, and others can be a great option for selling your used GPU. These platforms cater specifically to tech enthusiasts, so you may find potential buyers faster.
5. ITAD companies and resellers: certified ITAD companies and IT equipment resellers like Big Data Supply Inc. will provide competitive offers. A huge benefit of selling to specialized ITAD companies is how they’ll handle the entire process for you, including secure data erasure (with certificates of data destruction) and pickup services. A great option if you are selling in bulk.
6. Local computer stores: many local computer stores buy and resell used hardware, including used GPUs. This is a good option if you want to sell your old hardware quickly, but you might not get the most competitive price.

Before selling your used GPU, here are some important steps to ensure a secure and successful transaction:

1. Clean and inspect the GPU: dab a soft cloth into some isopropyl alcohol and wipe the GPU’s exterior. You can also use a can of compressed air to blow away any dust and debris that may have accumulated inside the old GPU. Make sure the used GPU is 100% clean and presentable to potential buyers. Also, use this chance to inspect the graphics card for any physical defects or damage.
2. Test the GPU: you can use software like FurMark or 3DMark, among others, to test the GPU’s performance. You can also run a few benchmarks or even games to manually test the used GPU’s performance. It’s best to document your findings, so you can present them to potential buyers.
3. Set a fair price: do some online research to see the market price of similar GPUs. You don’t want to sell your used GPU for too little or too much, but consider factors like its age, condition, and current performance.
4. Take high-quality photos: capture detailed and clear photos of the old GPU. The photos should highlight the old GPU’s notable features and physical conditions, including any defects or damage. Good visuals can be very important in attracting potential buyers, so don’t underestimate this step.
5. Ensure secure packaging: if you need to ship the used GPU on your own, make sure to use a sturdy box or appropriate packaging materials to protect the used GPU from any damage during shipping. Consider using cushioning materials inside the box to add further protection for the old GPU unit.

The expected lifespan of a GPU can vary depending on several factors, including but not limited to the make and model of the GPU, usage patterns, the environment in which the GPU is used, and individual hardware quality. 

However, we can expect an average GPU to last anywhere from 3 to 5 years, and exceptionally well-maintained GPUs can reach 8 years or more of life expectancy. Factors such as heat management, the level of stress the GPU undergoes, and overclocking may impact its longevity.

Yet, when it comes to replacing GPUs, we have to consider that even if the GPU is still in fairly good condition, new computer games and graphics-heavy applications (i.e., video editing, 3D, machine learning) tend to become more demanding, which will indirectly shorten the effective lifespan of GPUs.

To extend the lifespan of your GPU, consider the following:

• Keeping it clean: when dust and debris accumulate inside the GPU, it can cause the GPU to overheat, which will decrease its performance. Regularly clean your computer and your GPU with a can of compressed air.
• Keep it cool: make sure the GPU is well-ventilated by ensuring proper heat management/airflow in the computer case. Invest in a good case fan or even advanced heat management technologies like liquid cooling. Keep your computer in a well-ventilated and cool room.
• Avoid overclocking the GPU: while overclocking the GPU can improve its performance, it will shorten its lifespan. Unless your day-to-day activities demand overclocking of your GPU, do not do it.

While it can vary depending on the make and model of the old GPU, condition, and other factors, the average price of a used GPU decreases by 50% of its initial price in the first year after it is released. The price will continue to decrease, albeit at a slower rate, and we can expect the used GPU to lose around 25% of its value in the next two years.

With this in mind, older GPUs can range in price from as low as under $50 for severely outdated and/or entry-level models to more than $1,000 for higher-end or sought-after old GPUs.

In general, there are a number of factors that can affect the price of a used GPU, and the most important ones are:

• Age: old GPUs will obviously depreciate more quickly than new GPUs. Also, when a direct replacement model is released, the GPU will depreciate faster.
• Condition: a GPU that is still performing in an optimal condition will depreciate more slowly than damaged GPUs in poor condition.
• Demand: GPU models that are in demand will depreciate more slowly (and, sometimes, may appreciate in price) than low-demand or obsolete GPUs.