Randomness that only punishes? So you're essentially saying that typical annual cost is going to be 63 a year, but if you are unlucky it could easily be over 120, and your best case scenario is 36? I have to imagine most people would pass.
The best case scenario to a customer in a year is that he pays exactly 0, which happens with probability (0.9)^12.
Does that one person return the item and try again for it to be free?
You can just disallow that?
That becomes a unreturnable product. It has some use-cases but loses it's utility.