Ok. Logitech G203 for $20 and a Redragon K552 for $45 - a tiny bit cheaper than a PS5 controller which retails at $70 before tax.
Windows you can literally get for free from Microsoft directly. You’re basically paying a license to get rid of the “Activate Windows” bit and to be able to change wallpapers, but functionally you can play games and do computer things with an unactivated Windows license. You can also opt to play on Linux instead since Steam offers Proton with their Linux version, and you can also use WINE for games that won’t run on Proton. Linux is also free.