I'd disagree with the above statement
If the PC is less than 2 Ghz then don't bother upgrading it as your power supply probably aint big enough, your RAM probably aint fast enough, your hard drive probably aint big enough or fast enough, etc etc. By the time you pay labour you'll save nothing. Sell the existing PC or keep it for earlier games, surfing the net etc.
Spend some biccies on a branded PC. I see botched DIY PC's all the time. You won't save any money with a DIY build and you'll have a much harder time dealing with warranty issues. HP/Compaq Presario are pretty good value at the moment. Get a dual core processor (AMD or Intel) as a minimum (but avoid anything with the words Celeron or Atom). Acer are the cheapest for a reason (read in to that what you will).
Summit like
http://www.itd.co.nz/product/i/252903.html
Add better video card (you can easily do that yourself), extra RAM etc as and when required.
Bookmarks