I used this mining calculator: http://btcinvest.net/bitcoin-mining-profit-calculator.php?diff=19339258.272387&dcosts=2000&diff_mincrease=10&blpbtc=25&dhsmhs=2000&btcusd_mincrease=10&btcusd=105.55&dpowcon=1000&dleadtime=0&pcost=0.25&calcweeks=48&action=calc

And that's at 10% difficulty increase/month, which is very very conservative in my opinion.  You probably shouldn't buy this. You'd be better off taking the money you were going to spend and converting them to BTC and then buying shares in a company like ASICMINER.