do you know the specs of your friends computer and what kind of games they wish to play please? for £60 - £80 dx9 card you will be looking at something like a nvidia fx5700 or maybe a radeon 9600pro or xt.
both these cards should play most newish games quite well if you lower the resolution and game detail a wee bit. look for the card that has the highest 'clock' and 'memory' speeds in 'mhz' for your money and you shouldnt go far wrong.
try having a look here for example click here have a google and you find a bargain. here is some more info may help your friend choose click here