well i bought my stuff all at once since i was upgrading from a laptop... usually when ppl upgrade they will keep their peripherals and their hdd, sound card, maybe case. so i guess ur right if u already have that stuff and u want to keep it. a new mobo, cpu, ram, and vid card can still cost alot tho. those are the main components, so for pretty good stuff: mobo-150$ cpu-300$ ram-200$ vid-250$ = 800$ thats not top of the line, but that will get you a nice system, for 1000$ u can get a rly nice gfx card or a rly nice cpu.