(I'm glad someone’s posted something about cryonics; not having enough karma points I can't make a post myself unfortunately. I apologise for the slight digression)
It seems that paying to be cryonic preserved is a rather bad investment given the current capabilities of preservation technology. The extent of damage brain and the lack of any evidence to show that it can indeed be repaired and rebooted (even if only in theory) rules it out as a valid method of self-preservation (as explained by these people -> http://hdl.handle.net/1800/6115).
However donating money to research aimed at improving cryopreservation techniques and developing the science to also revive patients is worthwhile. It's a simple matter of optimization. On the one hand you can have a large number of people pay a large amount of money toward the imperfect preservation of what amounts to an approximation of their brain structure as opposed to a large number of people contributing a large amount of money toward developing an adequate method for preserving/reviving a much more exact approximation of their brain. Moreover the added contributions will reduce the time it takes for technology to reach this level, increasing massively the number of people who will have access to a decent method of self-preservation prior to their death.
Though there is some point to only a few people going for cryonic preservation. Doubtlessly their brains will prove invaluable to generations in the distant future in understanding the psychology of our times and provide them with information about our times that you wouldn't find in newspaper archives. However (ideally)these people would be persons of notable intellect, experience or creativity. (Chances are that brain preserved with current methods will able to be scanned and emulated far before it can be repaired/restarted. Hence it is less likely that they'll be revived by our descendants.)
All in all I figure Larry King should be investing in cryonic preservation research, not in being cryonically preserved (yet).
I agree with your point that a person who does not trust presently available cryonics should still invest in research. However, it does not necessarily follow that the optimal expenditure of a given dollar from any source is on research. A person may have a high enough estimate of the probability of it working adequately for it to be more worthwhile to purchase an existing cryopreservation than donate to research.
Or they may think research has hit a point of diminishing returns which cannot progress further until mature nanotech is available. Alternately, ...
I know celebrities cryocrastinate just as much as anyone else, but King seems like the kind of guy to go through with it.
http://www.cnn.com/2011/12/02/showbiz/larry-king-i-want-to-be-frozen/index.html?hpt=hp_t3