Well, there's cheap and cheap. Any medium-sized city or town should have a computer store that stocks 3rd-party parts, etc.
Unless you're going for a flamin' gamer's machine, $1,100 should buy you plenty. I build my PCs (well, since the 286 days, I actually bought the 8086...
You have to nail down what you want, first. The technology changes every 3 months, so no matter how long you wait, something 'better' will come along by then.
I have an Athelon 2000 in my 'elder' machine (about 7 years..

ASUS Motherboard, 512 meg o' memory (wonder if they make anything that small anymore..

Only 2 drives totalling 120g (but they were state of the art in '01..

As for a terabyte drive; do you
really need one? I know the price has come way down, but if you go for a few hundred gig (gad...my first HD was 30 meg, and I didn't know how I'd fill it..

and save some buckaroonies...
As for a processor, there's 57 varieties...

There's single, dual, and quad-core, with prices to match. Memory's not to expensive anymore.
You'll probably wind up with a version of Vista. I'd look at the minimum system requirements for that, and let that be your 'floor'.
I get stuff from a place called 'Intrex', in NC. Doesn't do you much good as far as going there, but if you want to see a sample of what's available....
a want the terabyte for my music and movies i want to do gaming and music and video editing. for the processor i want amd and the os is either vista ultimate or xp 64x edition (need 64x to support the ram) umm yeah