There's a possibly-important probability missing from your analysis.

For it to be worth paying for cryonics, it has to (1) work and (2) not be redundant. That is: revival and repair has to become feasible and not too expensive before your cryonics company goes bust, disappears in a collapse of civilization, etc. -- but if that happens within your lifetime then you needn't have bothered with cryonics in the first place.

So the success condition is: huge technical advances, quite soon, but not too soon.

Whether this matters depends on (a) whether it's likely that if revival and repair become viable at all they'll do so in the next few decades, and (b) whether, in that scenario, the outcome is so glorious that you simply won't care that you poured a pile of money into cryonics that you could have spent on books, or sex&drugs&rock&roll, or whatever.