I almost wish that it was price fixing, at least then we'd have hope that somebody would catch them at it. No, this is much more nefarious: lack of competition and relatively low supply. If AMD couldn't sell their 79x0 cards for these very high prices, then they would lower them. That won't happen as long as kepler is just a rumor at obr and tsmc is still getting production ramped up. Prices will natually soften up later this year as production increases and we start to get more concrete info about kepler, and they could (hopefully) really drop if kepler has a direct competitor to 7970 (as we've seen recently with gtx 570 vs 6970 and gtx 470 vs 5870). Only thing to watch out for is if the bitcoin/amd love affair continues, then amd prices might be artificially inflated again as they were in 2011.
See that? A completely logical explanation that doesn't involve any sort of conspiracy whatsoever. That doesn't mean that there isn't one, but I wouldn't waste too much time on this one.