New PC for general use and gaming, low budget

Hi, I'm looking to buy a new PC that is fast and can play all the recent games like BF3 and FC3 on high/highest graphics, but I cannot afford a really expensive set. Would this be a suitable build (from ebuyer) and can you see any ways I could make it cheaper, or anything I have missed? Thanks a lot  

Extra Value 8GB DDR3 1600MHz Memory £24
Asus P8H61-MX R2.0 Socket 1155 8 Channel HD Audio mATX Motherboard £37
Casecom KB-7760 Black ATX Midi Tower Case - No PSU, No Case Fans Included £12.60
Xenta USB 2 Channel Soundcard with volume control and Headphone/Mic Input £4
Casecom Silver 500W PSU - With 12cm Red LED Fan, 20+4pin 1x SATA, 1x PCI-E £16
Intel Core i5 3470 3.20GHz Socket 1155 6MB L3 Cache Retail Boxed Processor £146
Sapphire HD 7850 OC Edition 2GB Dual DVI HDMI DisplayPort PCI-E Graphics Card £150
Hitachi 320GB Travelstar Hard Drive £33

£423 total

Im a complete novice at building my own PC so please point out any glaring problems, however obvious,

Thanks again