I've bought used CPUs off eBay lots of times, with never any failure. Low power versions are often hard to find any other way, such as a 35W i3-4150T on this PC, a 35W i3-7100T 4 years ago, and a 65W/45W A8-8650B most recently purchased.

The socket FM2 came out in 2012.
That's a decade ago. Given Moore's Law - you should upgrade. IMO.

HDD, fans, USB flash drives - they break down in my experience.
But not CPUs or RAM.

Your storage devices can be re-used.
Although HDD does have a limited life span.
You're RAM cards can be re-used. But if you choose to have the latest motherboard - then they will likely run DDR4 RAM and not DDR3.

If you're looking for bang for buck - then pre-owned PCs can be bought at good prices.
Make sure Amazon or ebay wlil proect you if the PC is unreliable.