Guessing $5 to $10 million?
From Golf Magazine:
Money for hosting an event ranges widely. If you’re talking about a U.S. Open, the amount the USGA pays in facility fees is substantial — north of $2 million when it “rents” a club. But clubs also share in the event’s revenue and receive additional funds to prepare and restore its course. In the past decade, Erin Hills’ total take was on the low end: $3.9 million. Oakmont was at the top end with $9.3 million, a third of it from merch sales alone.