I think it depends a lot whether you're paying out of your own pocket. Sure, there are other considerations (e.g., I'd agree that Marriott is stronger in the luxury segment). But it's a fact of life--especially outside the US--that Marriott-branded hotels tend to be the most expensive.

I see run-down CY's and Moxys' charging more than Hotel Indigos (despite comparable-quality location) all the time.

A previous poster's interpretation is spot-on IMO. Marriott and Hilton are the go-to brands of Americans abroad. (For upper middle management types and such, Hyatt plays a role, too. But for the most part, it's Marriott and Hilton, especially Marriott.) And hotels know Americans have little vacation and hence great purchasing power when traveling for pleasure and decent travel allowances when traveling for business. Marriott pricing very much reflects this.