If you have free electricity and if the prices remain stable at where they are, I mean more than $450, then there's a chance you can get out with some nice profit in the next few months, but that too before halving, as nobody knows what will be the scenario after halving takes place...
There are chances that people might lose interest in Bitcoins, or might there happen something like a big pump that could take BTC to somewhere that will drag everyone's attention towards it again...
There are chances that people might lose interest in Bitcoins, or might there happen something like a big pump that could take BTC to somewhere that will drag everyone's attention towards it again...
Well with the price 450 USD and having a Antminer S7 + a energy rate of like 10 cent / kW the ROI period is less then 120 days. It's a little bit high yes but 'doable' even more if you expect the price to rise even more.
But looking towards the difficulty that skyrocket big time see:
https://bitcoinwisdom.com/bitcoin/difficulty
It's very risky again. Therefore i wouldn't advice to buy mining gear right now.
After 120 days, you still haven't paid off your S7, unless you got it for less than $600, or unless difficulty starts to fall off below 5% every two weeks. I have no idea what assumptions you made to get a payoff off of 120 days.
Maybe you expect the price of BTC to increase faster than difficulty, and you got the S7 for "half price" maybe you can make it work out.
I think that a 120 day payoff for an S7 require an incredible number of unlikely assumptions.