Just in case you’re wondering, yes GPU Bitcoin miner out of the picture, USB Eruptor price gone down to $30 a piece in ebay and private sell on forums and email via paypal. Eventually these USB Eruptor will be obsolete as well with the GPU and miners like ASIC Butterfly Labs and KNCMiner will hit the market fully and is impossible to make a penny with USB Eruptors. If you buy USB Eruptor today for $30 a piece, you will get your money back in about 5-6 months or more not less, based on the difficulty estimate and price of bitcoin, if the BTC price will not fall further.