http://btcinvest.net/bitcoin-mining-profit-calculator.php - check it out! ✓ next difficulty + time left ✓ customizable monthly (diff + USD/BTC) increasements ✓ device lead time ✓ update: auto-compares device costs to BTC-buy profit ♥ 1btciBCKb59TbzNj5QzC2EXWDARxtJL1f