The 7800XT looks 3% faster than a 6800XT while a 7700XT looks like its the same speed as a 6800, based on the prices for these cards right now then I can't see how AMD can come in at any more than £400 for a 7700XT considering you can get a 6800 with 4gb more VRAM for £425 and £500 for a 7800XT considering you can get a 6800XT for just under £500.