need some help on which to buy

[spreedin]

So i have a chance to buy
 Cointerra TM4 which does 1.4-1.7 for 450$ local pickup
Antminer S2 for $400 + $30 Shipping
(2) Antminer s3+ for 400 plus $30 shipping

I have 2 S3+ already and they work flawlessly so the S2 would be a good choice but the Cointerra seems legit he has 8 for sale only issue is power i would have top setup a 20 amp circuit for each box

So my questions are since they are all close in price, which would be more cost effective on power to maximize profit....

any and all help, opinions are welcome and appreciated

thanks in advance

[activebiz]

the tm4 looks like a good deal. u can find mining hardware comparison from https://en.bitcoin.it/wiki/Mining_hardware_comparison combined with a profitability calculator like one from bitcoinwisdom u should be able to find the best miner with good profit.

[BTCish]

Take that S2 miner