Not far off with your power figues a 4 card rig will drain 1200w, also the coins have gone up in value some, bitcoins at around $700-$1200 and litecoins around £30 bitcoins mining is all asics now there no money for gpu miners, litrcoins are know as skrypt coins and are asic safe for now so they can only be mined woth gpus altho there are fgpa miners being developed whist we speak! You will always recoop your investment when you cash in your hardware waste heat can be used to heat your house, theres also other methods to make money with gpus if the coin market drys up which it wont!! Also electricity is not a issue as my mums on a capped plan where she pays for so many units then the price drops, my friend who runs a few of these rigs is on a pay meter as is parinoid police are going to bust his door down thinking hes operating a canabis farm haha he will have fun explaining that one