At least one Koch brother has signed on to Donald Trump’s presidential campaign by agreeing to host a $2,700-per-person fundraiser in his Cape Cod home.

Bill Koch, the 74-year-old founder of Oxbow Carbon, will host the event at his home in Oyster Harbors, Mass., on Saturday. Guests will include Republican National Committee Chairman Reince Priebus and former Massachusetts Sen. Scott Brown, according to a flier for the event, as well as Trump finance leads Steven Mnuchin and Lewis Eisenberg. Donation levels begin at $2,700 for individuals and run as high as $100,000 per couple.