$175 per miner for hosting might be a bit expensive as these miners, on .04 electric, are only netting around $210 and that drops with each difficulty increase - so the net profit to the buyer is only $35 per month per miner. at a cost of $3500 to $4000 per miner - that puts their ROI at 100 months for the $3500 units and 115 months for the $4000 units - and that is assuming the profit stays where it is, we all know that wont happen and we all know that these miners wont be profitable in 24 months let alone 100 months.

If you were charging the cost of electricity and $50-$75 a month, that would put the ROI at 21 to 25 months, again assuming that difficulty holds where it is and that BTC price does not drop. Some might find that deal a tad bit more plausible.