I don't think this can be considered a risk, more of a poor decision due to not considering all the variables.

Variable 1) price of bitcoin collapses next year (just a theoretical situation, not bearish on the market)
Doing so greatly decreases the amount you will receive from month to month.

Variable 2) Tax implication of cryptocurrency is still in its infancy. In any case, short term capital gains are not favorable for investments.

Variable 3) - overall power of the hashrate over time. My cousin and I run a small business mining, right now we are just trying to break even. That being said, when we started, an antminer with 13.5 ths/sec, got us $18 a day, now we are down to $12 a day. Over a 3 month period we are seeing a collapse of 33%.

Antminers are being pumped out on a daily basis and as such, are inflating the overall hashrate in the entire mining industry. Not to mention, the future miners that are expected to come out that offer even more hashrate. Therefore, a hashrate of 134 ths/sec will most likely not get as much of a return one year from now as it is today.

I'm not saying that this is a bad investment, however, I am saying the returns are inflated. After the first year you may or may not get your money back (at the current price amount). Of course, Returns will follow after that (again, considering the price stays the as high as it currently is or increases to a higher amount) however, as to how much you will get after that, is up to the market.

The really troubling part is the $47 mining fee. If its percentage based, you'll be ok. But if its a flat fee, the company is ensuring that they will always make money on you.

What happens when the reward is smaller than the fee? do you have to pay them back?