His plan is only a plan to live healthily. In that he is like David Murdoch [1], who has the fortunate coincidence of living longer, being very wealthy, and having long had good health practices. But once you get past your 70s and 80s, the odds of living longer start to have much more to do with your genes than your past health practices. 75% of everyone with the best diets and healthiest lifestyles die before reaching 90 [2]. 99% die before reaching 100, and your progress in that territory is strongly dependent on genetics. This fellow has about a 50/50 chance of making it through the next 10 years, and only very low odds of making to 100, and there is actually very little he can do to make those odds better that is not also available to the rest of us.
We live in an age in which access to specific types of medicine is very flat. If you have $30,000 and medical insurance, there is nothing that a billionaire can conveniently buy that you cannot also go out and get if you do the legwork and phone calls yourself. Medical tourism, clinical trials, etc, etc. The billionaire can buy a fleet of doctors but he cannot buy a form of medical technology that isn't yet available to other people.
He can of course, create new medical technologies by funding their development, but then it is still available to everyone at the end of the day.
Remaining life span for the old is strongly dependent on progress in medical science, however: the transition of the next few decades from medicine that is only a matter of crudely patching over the symptoms of aging to medicine that addresses the causes of aging. An example of the former is alteration of gene expression through drugs, or introduction of reprogrammed stems to enact repair. In neither case does that address the reasons why gene expression changed, or why native stem cells are not doing their jobs. An example of the latter is breaking down the build up of metabolic waste products like lipofuscin constituents [3] that harm cellular operations and housekeeping machinery, and are increasing prevalent with age.
The future of medicine must be something that evolves from the Strategies for Engineered Negligible Senescence (SENS) [4], a way to repair the underlying cellular and molecular causes of aging to reverse its course. Everything else that fails to deal with underlying causes is just patching over holes in the dam, or trying to keep an old engine running without replacing any parts: the whole thing fails catastrophically no matter how much expense you go to, and the expense keeps mounting regardless. That is present day end of life medicine in a nutshell, and it must change to preventation and repair of known causes.
Even with far more funding than is presently the case, SENS implementation in laboratory animals is 10 to 20 years away.
If you are in late life then your only practical option for anything other than death and oblivion is cryonics [5], the low-temperature vitrification of the fine structure of the brain in which the mind is stored, done against the possibility that future medicine can restore a vitrified brain to life. (Or, depending on your viewpoint, that it can be scanned and run in software, but that doesn't seem like a very helpful end result to me. A copy of you isn't you).
So as I said at the top, this fellow has a health hobby, but he really isn't doing anything material other than having a good time, and perhaps deluding himself as to how well he is impacting his life span. The only material things worth a damn are (a) 80/20 good health practices like regular moderate exercise and calorie restriction, (b) funding the right rejuvenation-focused medical research, things like SENS that may pay off greatly in the next few decades, and (c) cryonics. Everything else is wishful thinking.
1: http://www.forbes.com/sites/nextavenue/2013/06/07/90-year-ol...
2: http://www.ons.gov.uk/ons/rel/npp/national-population-projec...
3: http://sens.org/research/introduction-to-sens-research/intra...
4: http://sens.org/research/introduction-to-sens-research
5: http://www.evidencebasedcryonics.org/scientists-open-letter-...