People with $100mm could buy their visa by making a unprofitable business and come in on the immigrant investor visa anyway. Or get a US friend to create a company where they have veto powers and come over on an L-1A and get their green card in 2-3 years due to no labor certification or waiting list. And their spouse can work also on a L-2 visa when they apply with him. Someone who has made a $100million could also get an O visa. Your a pretty remarkable person if you've made $100 million.

Also if you have $100 million and don't setup your income to be indirect through companies and such, the USA taxes all international income, even if you've never lived or set foot in the US for years, and has an expat tax if you give up your green card or citizenship explicitly made for rich people. The usa is the only country in the world to do this and makes it unattractive to actually get a citizenship from them if your wealthy. You can still do business and profit from the country quite well without being a citizen and at that level you could do business in the country part time coming in on B-2 visas. The consulate would have no problem giving you a 10 year multiple entry B-2 visa since you have a very very very low illegal immigration risk.