He's an idiot. He pulled off one of the most incredible stunts I've ever seen. Not only does was he able to find and extract the gold over a mile down, which is incredible, he was also able to rally over 100 investors and raise capital. Ironically this is basically how capital markets originated, from shipping ventures not unlike this one.

He should have given the investors their money, taken his performance fee, and not spend up to half of his remaining lifespan (and probably around 3/4 of his remaining health span).

On the other hand, if he has grandkids and he manages to give them say 100mm instead of 20mm, he may feel it was worth it genetically.