The hotel that we booked through Expedia was excellent:

This place was a rare find. A boutique hotel, with maybe a half dozen very nice rooms located above a French Bakery and restaurant. Two blocks off the main drag, I really doubt we would have ever even seen it, had it not been for Expedia. We paid just $44 per night (figuring in a 10% discount for paying cash). In a heavily touristed area like Tulum, that was a heck of a good deal! (Prices quoted were correct in 2015; they’ve gone up since then, but it’s still an excellent value.)

Calle Alfa Norte Esquina Con Sagitario, Poniente S/n Colonia Centro, Tulum, QROO