If you already have the ram and use XP it's fine. Anyhow, with the VID cards after a year it's pretty certain you'll get sick of lowering res and details each time a new game appears. It depends really how much do you care about high details and stuff like this, I for one change the VID card each year because a 10% OC on any VID architecture usually doesn't bring much.
BTW willbushby, budget was Â£400. So a bit over!