The real problem is that the calculators can only make a guess at the potential increase in hashing power over the next few weeks and months.. This in turn also depends upon manufacturers sticking to claimed delivery times... Given that Terrahash+ units are not far away then the potential lifespan of < 100GH/S units has to be questioned - it may well be as mentioned that the most profitable option is to sell the equipment now whilst it still has value before these big guns hit the pools. But of course that is not much fun .

Melb