That’s more valuable than buying a bigger yacht.
Of course, once the knowledge is gained and a problem is solved, someone somewhere will reproduce the same thing for a fraction of the cost. The real cost is the research.
Billionaires could easily solve baldness, aging, or any number of problems for themselves without releasing anything.
In fact, Alphabet is already openly doing this with its ultra-secretive Calico company that is sucking in lots of researchers and locking their discoveries (if any) in a private vault.
And if the technology was patented in some way that would also lead to disclosure and not all regions respect foreign patents anyway.
Rather, how did he put that on?
[1] https://static.ffx.io/images/eed406d72af2384b0d58edd9903e55c...
Yes Follicular unit extraction (FUE) is possible, it has less yield than strip harvesting but if you don't need to maximize donor area it's a good option to avoid a scar (you'll still have micro scars from extraction area but it's much less visible).
But in Elon's case, it's clear he underwent strip harvesting for at least 1 implant.