It sounds like they treat the idea completely in FAR mode. Or as a fancy new idea their bight son has come up with for the day. And sadly I have no idea what to do about that. You could of course make the money on your own and see if they would consent if you sign them up and/or state that you plan to freeze them anyway. But that might not work out that well either.
But i seriously doubt that your parents are against any for of life extension. Most people are not. At least do not state so. Using seat belts, doing checkups at the doctors. Even dentistry qualifies, since each of those defy the 'natural order' of things, which was to be dead by about 30 from toothdecay. Everyone who takes his medicine is pro life extension. You just need to move the border a bit.
Are you signed yet?
Disclaimer: I am not signed, and have not made up my mind about the usefulness of cryo myself yet. It might be totally useless. But the counterarguments usually brought up against it are not particularly convincing.
I'm currently trying to convince my parents to sign up for cryonics.
The problem is that they are completely opposed to the any form of life extension and/or immortality (and that’s without even mentioning something as "strange" as cryonics). Unfortunately, being their child, I have the intrinsic property that I can never know more about life then they do. The only thing they will believe are scientific studies from respectable scientists (a respectable scientist being someone who only says what they want to hear and is not me)
I have the arguments I gathered from Less Wrong and the Alcor Library. I’m focusing on my mother since my dad is impossible to convince without her support.
Her argument is that when you live for a very long time/forever wars are almost guaranteed to occur at least once in your lifetime and she doesn’t want to live through those. I asked her when, given that we could perfectly predict the future, we would know a war would break out tomorrow she would commit suicide today. Her answer was yes, as she couldn’t bear losing any of us and doesn’t want experience a war. I pointed out how I would feel if she died but she just dismissed the entire thing as crazy.
My parents aren’t religious at all, so that’s one less bridge to cross but for all the rest I would greatly appreciate anything that might help convince them.