An expensive coffee costs $5. For a person that makes $100,000 that's 0.005% of annual income.
Musk's annual cost would be $33,120 for all three kids. I don't know his annual income and because a lot of his worth is in stocks it's probably hard to figure out and highly variable. I'll do some pretty stupid math and say he's worth 185 billion and he's 52, so he's made 3.5 billion a year.
Musk is fighting to pay an annual cost for all three of his three kids of 0.0009% of his annual income, a amount proportionally less than what many spend one day on coffee.
Again, no. Musks networth was somewhere around 160 billion because of stocks in the stupidly overinflated tesla. The tesla bubble is already inflating like hell and with that I'm sure he's losing networth like hell. If he continues current course he'll be bankrupt withing a few years.
Either way, the money he has in his bank accounts is NOT the same and probably in the tens of millions tops.