These units will never earn back more then 0.3BTC if delivered by next diff update.

http://btcinvest.net/en/bitcoin-mining-profit-calculator.php?diff=390928787.63809&dcosts=8000&diff_mincrease=30&blpbtc=25&dhsmhs=5000&diff_mincreasedecrease=3&btcusd=190.75&dpowcon=30&btcusd_mincrease=1&pcost=0.25&calcweeks=32&dleadtime=1&action=calc

If they are priced over 0.3BTC then they will be insanely overpriced, and a terrible investment.