that's a really old PC if my lookup of the specs is right: Phenom II 955 in a 760 Mobo (circa 2010 chip), with a GTX 650 (circa 2013 gpu).
not bad for the time, but with only 200 pounds, I'd upgrade the video card. a GTX 1050ti should work great for well under 200 pounds. I wouldn't go higher because the cpu will struggle with any more powerful card.
Alternately, if you can save up, AMD's new Ryzen chipset will be out in a couple weeks (Feb 28-March 3)