nVidia's high end Fermi is going to have to be priced even higher than that if they are going to make a profit on it.
not quite, overall a Fermi 380 card will only cost them around £40-£50 more to manufacture than a 4870 - there are massive profit margins on high end GPU's, so they will stay fairly competitive on price/performance unless ATi decides to really kick them in the nads with a price war, but personally I think ATi will be quite happy to go with £200 5850's, £270 5870 and £480 5970's and let Nvidia stick their cards in the £300-£400 range.