This is a big one. His golf trips are on track to cost the US government $100million this year alone. Golf cart rentals alone are greater than the Presidential salary, and of course he has rejected proposals for the Secret Service to just buy their own carts which would be significantly cheaper.
He also spent a great deal of time traveling to his own properties during the first term. www.politico.com/news/2020/01...
Also, foreign (and domestic) leaders, dignitaries, lobbyists, etc. gain access and influence by staying at Trump properties. Trump also personally profits from such stays.
If Obama had laundered bribe money through a hotel he owned, he would have been impeached. oversightdemocrats.house.gov/news/press-r...