I've got a Microsoft PS/2 keyboard from a few years back, some generic 5 button USB mouse, a TF2 mouse pad, and a 1080p monitor. Which doesn't make much sense for PC gaming considering I have an HD 5770, but...damn, Xbox 360 and PS3 look great on it!
Yep. I don't see the need to spend a ridiculous amount of money on "gaming" peripherals, when I've been using standard ones to play PC games for as long as I've had a PC. And I've done just fine with them.