Wait two weeks - let the Gtx275 get going and all prices will have to re-adjust. Gtx250 is a waste of time imo. 192 shader Gtx260 are plummeting - 55nm 216 shader will follow shortly as will ATI 4870 and all of those are a better bet than a 250. Yes, you may end up paying £40/£50 more, but it is a better investment.
Keep your eye on nVidia Gtx260 - (55nm) 216 Shader - and ATI 4870 1Gb if you want a really good bargain, but just hang on for a couple of weeks (they are already cheap as hell to be honest)
ATI 4890 is a classic - it can run everything a close race upto x2 cards - and they are already down to £195 - there has to be a massive price decrease in the coming weeks. It's idiotic at the moment - there are Gtx250 costing MORE than Gtx260! It's all gone a bit mad.
---------- Post added at 21:21 ---------- Previous post was at 21:09 ----------
http://www.ebuyer.com/product/161605
vs
http://www.ebuyer.com/product/160750
The Zotac has 1Gb - Big Deal - anyone that buys that over the Gainward is out of their head.