There is always a cheap PC just around the corner no matter where you are.
My latest build or rather builds, cos I have ended up with 3 of the buggers, is a Media Center PC for as little money as possible.
The first PC was given to me, I upped it as much as I could, GFX,Sound and CPU all for under a tenner but it was still iffy.
Few extra bits and I ended up with an AMD x2 4800 with 4GB RAM, GT210 GFX, Asus Xonar DG Audio, and 400GBHD and its cost me around £50 in total.
Im actually fairly chuffed with it. i might even use it properly too... I only knocked it up cos Im bored but the idea is a better one than I thought.