This might not be the answer that you are looking for, but a good set of peripherals for my PC. A good mechanical keyboard, 3 decent screens, a stand to mount

This might not be the answer that you are looking for, but a good set of peripherals for my PC. A good mechanical keyboard, 3 decent screens, a stand to mount them up high and make room on my desk, and a few other smaller things. Those parts have done more for my career and sanity than anything else I could have spent my money on at the time. I spend 40+ hours a week at or around this desk, I want it to be comfortable and work well for me. Not to mention that even if something makes me 1% more productive, it's worth it to spend $1000 a year on it and still "break even" in terms of cost (in theory)