Bitcoin Mining Farm outline

Today I came across an ebay listing for 52 Antminer S5 miners for $23,500.00:

52x Bitmain Antminer S5 SHA-256 BTC Bitcoin Miner 1155GH/s @ 590w *52 Pack*

I got to thinking about running a mining farm:

Miners: $23,500.00

EVGA 1300 Power supplies one supply ($191 each) for 2 miners: $4966.00

Total capital outlay: $28466.00

Current bitcoin price: $270

Average daily reward per miner: 0.0125 BTC or $3.37

Average power consumption of S5 miner: 13.88 KWH

Cost of power in Portland: $0.19/KWH

Using these figures these 52 miners would mine:

$175 per day, or $5265 per month

Consume 722 KWH of electricity per day or 21,653 KWH per month

Costing: $137.18 per day or $4114.07 per month

Profit: $38/day or $1151/month

It would take 25 months to pay for the miners.

In addition to the above costs, I would definitely need to add some cooling capacity, and pay for that electricity also.  Needless to say I won’t be investing in a mining farm