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Whenever you build a new PC, you need to decide which components you'll carry over to the next build, and which ones stay behind. While power supplies, storage drives, CPU coolers, and cases can often be used for 2–3 successive builds, other parts often rot in your drawer for years. Hoarding old components for "just in case" DIY projects erodes their value until it's too late to sell them and get back some of your investment. Retaining older components is understandable if you're a tinkerer or regularly repurpose old hardware. However, if you know you'll just sit with your old PC parts for years, it's best to sell them while you still have takers.
Monitor
Sell it before it becomes outdated
Gamers majorly use one of three categories of displays: older 1080p low-refresh-rate monitors, recent 1440p mid-refresh-rate models, and newer 1440p or 4K OLED displays. Switching to a new gaming display leaves you with your old monitor, and you need to decide whether to retain or sell it for cash. I've always sold my older monitors immediately after buying a new one. I did it with my 1080p 75Hz display, and recently with my 1440p 144Hz screen. I'm not a multi-monitor guy, nor do I have spare systems that would benefit from a decent screen. So, I prefer selling my old monitors while they can still fetch a good price. From both my monitor sales, I managed to get 40% of the initial spend back after using the displays for roughly four years each.
If you know yourself, and are confident that your old monitor will do nothing but gather dust for months or years, sell it while it's still relatively modern by gaming standards. If you really need a display for another project in the future, you can probably find a pre-owned model for significantly less than what you get from selling your old monitor.
Motherboard
Budget hunters are on the lookout for old platforms
So, you finally upgraded to a new platform, and built a PC from scratch, replacing your old motherboard with a bunch of other components. You might have stuffed the board in its original box and forgotten about it, but unless you plan to build a NAS or retro gaming PC with it, selling it is probably the way to go. During the first few months (or years) of a new platform, the preceding one stays relevant, especially for budget gamers. This window of opportunity is ideal for getting some of your cash back. You can get more buyers if you sell your motherboard along with the old CPU and RAM, and might even be able to demand a higher price compared to selling them individually.
I failed to do this when I moved from my B350 system to my current B550 build. I still have the old motherboard, CPU, RAM, and even the PSU and case from the previous machine. I probably thought they'd come in handy for a spare PC one day, but that day hasn't arrived in three years.
RAM
Spare memory is rarely usable in new builds
As I mentioned in the previous section, RAM should usually be sold along with the CPU and motherboard to secure a better deal and avoid the hassle of finding buyers for individual components. That said, if you have a few DDR4 sticks lying around, they can still fetch a good price on the used market. Mixing old memory kits with your new ones to increase your total RAM capacity isn't without inherent stability and compatibility issues. Hence, it's best to sell if you don't intend to repurpose your old RAM sticks in a home lab or NAS. People who are looking for cheap memory for their DIY projects will be glad to scoop up your old kit. In the current PC hardware market, RAM prices have skyrocketed 4–5 times. You can probably three times what you paid for your 32GB DDR4 kit — make hay while the sun shines.
CPU
Ancient chips can still fetch a decent price
When you're finally done with your CPU after 5–7 years, and move to a modern chip and motherboard, your old hardware is mostly useless for you. Unless you want to build a streaming server, home lab, or test bench, that old CPU should be sold as soon as possible to make the most of your initial investment. While it's probably 4–5 generations old already, it can still fetch a good price from the right buyer. Someone looking for your specific model or an older-gen, high-core-count chip for cheap could be ideal. Otherwise, you could look for CPU collectors if your chip is especially ancient. And selling your CPU along with the motherboard and RAM is always an option.
Graphics card
Don't be sentimental about it
You might not retain your GPU as long as your CPU, but it can still be several generations old by the time you switch to something newer. That said, used GPUs are some of the best parts to sell on the secondary market. Thanks to an ever-increasing demand for GPUs and high prices of current-gen cards, your 4- or 6-year-old GPU might still be in high demand. If it happens to have more VRAM than many modern offerings, or enjoys better compatibility with older software for specific home lab workloads, then a whole different market opens up to you.
Unless you want to retain your old GPU as a backup or wish to turn it into an external GPU, you should strongly consider selling it. I got half my investment back when I sold my GTX 1050 Ti back in 2019. Your mileage may vary. Lastly, if you need a spare GPU in the future for a streaming server or secondary PC, buying a pre-owned, entry-level card will be better than holding on to your gaming GPU.
Be honest with yourself, and sell while there's still time
PC components don't last forever, and there comes a time when they become essentially worthless. If you aren't one to repurpose older hardware, then the smart way to deal with it is to sell it when it still holds value. Even if you require a spare component down the line, you can always get a cheap model on the secondary market instead of hoarding something that can fetch a great price. It's about timing, and knowing what you'll realistically use in the future.
