To do good in general, and possibly get cryopreserved depending on the outcome and time the research will take.

It's true, my donations alone wouldn't advance cryopreservation much. It's also true that the two pounds a month I pay to the NSPCC doesn't do much to prevent cruelty to children, but I'm not the only contributor. Providing enough people contribute to the cause cryopreservation would be advanced a good deal. It's like game theory, it's better for everyone to contribute to improving cryopreservation than cryopreserve themselves with current technology.

Your life wouldn't be saved anyway. As I was saying, even if you take the possibility of regenerating brains preserved with the current method as a given, it's unlikely it will happen before your brain is disposed of. Chances are we'll have the technological capability to emulate a brain before we have the capability to regenerate one.