I think that in a country with very cheap electricity (or somehow free for you) you can buy around 4 miners and get your money back in 6-8 months. However, you are very lucky if your miners are still working, because they have a tendency to die. Oh, and they are too loud, so you need a space where nobody lives. I wouldn't start mining, because it's risky, loud and taking a lot of your time.
Come on, now. Miners aren't too difficult to keep running, and they rarely die unless you have the S9 or a bad S7 batch and you take good care of them, like dusting and occasionally checking on them to make sure they run well. Most aren't incredibly loud, I keep mine in my basement and one S3 in my living room with a modified fan, so noise isn't that bad. Electricity is the true part, and that's where most people don't meet the criteria for mining, but the rest is generally easy stuff.
