i dont see it is profitable to buy any ASIC miners now, only if u have free power suply
Even if you have free power you may be tempted to do something more profitable with it than mining. Not getting payment for electricity isn't funny.
I think mining is the most profitable for free electricity, maybe baking cakes too...
The way things are now, buying a miner will be a loss even with free electricity and no miner wear whatsoever. Difficulty grows exponentially and the profit from a miner will never reach the cost of the miner.