£67 ASRock H77 Pro4-M micro-ATX LGA1155 motherboard
and £93 Intel Core i3-3220
Ivy Bridge dual-core 3.3 GHz LGA1155 processor with HSF
or £77 Asus H87M-E micro-ATX LGA1150 motherboard
and £161 Intel Core i5-4570
Haswell quad-core 3.2 GHz LGA1150 processor with HSF
£49 2x4 GiB PC3-12800 Crucial BLS2CP4G3D1609DS1S00CEU (DDR3-1600, CAS 9, 1.5 V) memory
£92½ MSI N650TI-1GD5/V1 GeForce GTX650Ti 1GB graphics card
or £165 XFX FX-787A-CDFC Radeon HD7870 2GB
or £150 EVGA 02G-P4-2660-KR GeForce GTX660 2GB
or £137 Sapphire 11200-14-20G Radeon HD7850 2GB
or £125 EVGA 02G-P4-3653-KR GeForce GTX650Ti 2GB
or £101 Sapphire 11210-00-20G Radeon HD7790 1GB
£50 1.0 TB Seagate ST1000DM003 hard-drive
optional £87 0.128 TB Crucial M4 SSD
£13 DVD-RW
£53 CoolerMaster Elite 342 micro-ATX case with 500W power supply
£65 Microsoft Windows 8 OEM 64-bit
Including the 20% VAT, I'm over your budget by 20.6%. PC components here in the U.S. have no VAT.
Another way to go about building a budget gaming PC would be to pick up a scratched-and-dented or refurbished Inspiron 660 with a Core i3 or i5 from the
Dell outlet store for a very reasonable
£264 + £22 delivery and then add your own gaming graphics card from the list above. The Radeon HD7850 2GB would provide an excellent gaming experience at 1920x1080.