I'm obviously speaking from a purely technological standpoint... anyone can re-price things and it happens day to day. So prices drop, and soon you can get two of them for more than the r700 but also with much higher performance..
Not possible at all or NV would end up with selling GTX280 below production price, when AMD would still earn money.
With R700 beeing 2x 55nm RV770 (which are much less complex than GTX280 so it's much easier to make them) and with GTX280 beeing 65nm giant.
So if these Vantage noumbers are true, AMD is in better situation than NV.