At the top of Google searches for "San Francisco Marriott booking" was the ad for SanFranciscoMarriott.GuestReservations.com. This site would sell you a room at the Marriott, at a markup of *35% to 85%*.
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sanfranciscomarriott.guestreservations.com
Guest Reservations
As an independent booking service offering over 100,000 hotels worldwide, we can get you the same deals you expect with a bigger travel agency or direct from the hotel.