That's $300m. Yacht can be another $300m. There are houses in all those areas going for over $100m, building something could cost more so, there's another $600-700m.
A couple golf courses could cost $300-400m each, depending on location.
So, at about $2b. If I start building property by buying houses next to each other, knocking them down, it could easily cost a lot more especially in very desirable locations where I'd have to come in with a lot of money to get sellers to sell.
Old war stuff could add hundreds of millions more.
And, there's almost no limit to sports memorabilia to buy.
Add in upkeep, renovations,l and taxes on all this plus cost of tickets which could be another several million a year and eventually it could get there if I kept buying cool stuff. Maybe some paintings a Statavarious or two.
You're right it would be hard it is a lot of money but, give me a year or two and I could get there.