The 15 year gain may be enough to get you over the tipping point where medicine can cure all your ails, which is to say, 15 years might buy you 1000 years.
I think you are being pretty optimistic if you think the probability of success of cryonics is 10%. Obviously, no one has any data to go on for this, so we can only guess. However, there is a lot of strikes against cryonics, especially so if only your head gets frozen. In the future will they be able to recreate a whole body from head only? In the future will your cryogenic company still be in business? If they go out of business does your frozen head have any rights? If technology is designed to restore you, will it be used? Will the government allow it to be used? Will you be one of the first guinea pigs to be tested, and be one of the inevitable failures? Will anyone want an old fuddy duddy from the far past to come back to life? In the interim has there been an accident, war, malicious action by eco terrorists, that unfroze your head? And so forth.
It seems to me that preserving actual life as long as possible is the best bet.
Question for the advocates of cryonics: I have heard talk in the news and various places that organ donor organizations are talking about giving priority to people who have signed up to donate their organs. That is to say, if you sign up to be an organ donor, you are more likely to receive a donated organ from someone else should you need one. There is some logic in that in the absence of a market in organs; free riders have their priority reduced.
I have no idea if such an idea is politically feasible (and, let me be clear, I don’t advocate it), however, were it to become law in your country, would that tilt the cost benefit analysis away from cryonics sufficiently that you would cancel your contract? (There is a new cost imposed by cryonics: namely that the procedure prevents you from being an organ donor, and consequently, reduces your chance of a life saving organ transplant.)