ge force fx 5200 256mb pci

so is there any graphics cards out there for about £50 that are better than the current card i have like at places like pcworld.co.uk

i have an agp slot but i am wanting to run doom 3 and hl2 and unreal tournament witch runs well slow on all high and i only like playing games on the highest setting

what do u mean cranked and surely a 6600gt or 9800 pro will make doom 3 run smothle on ultra settings becouse i got my ge force fx 5200 to run quite good on ultra but freezing all the time and i bet a 6600gt will be 10 times better and i bet the 6600gt and 9800 pro costs load and is ther away to improve my graphics card performance to like a fx 5700 becouse i overclocked my fx 5200 from 250 mhz core clock to 350mhz and memory from 400mhz to 450mhz but i then restored the clock setting to default becouse i think i would of fried my 5200 on stock heatsinks but i could be wrong i was wondering if u could actually help me on this too well the whole post

there is an option in the graphics settings on my computer it says additional properties and i cant access them it wont let me click it and i dont know how to get into them is there a way