I'm currently running an AMD 6700 HD in my rig. It's a bit old now, but it was £120 when I got it. I think it's the bottleneck in my system, as it's running at 100% on medium settings. I'm pegged at 60fps by choice, but in a RES I'm getting down to 45fps and in station 30fps.
My CPU never goes over 30%.
Is there a definitive table or some other way to compare entry-level GPUs with the 6700? I can't justify £120 on a replacement, but it might be that the current crop of entry-level cards are better than this thing despite their price.