Best backpacker place to travel in Mexico?

My friend and I want to take a little trip to Mexico to hang out on the beach for a week. I want to find a place that isn’t too expensive to fly to (so oaxaca coast is out). I just went to Tulum and really liked that. I really didn’t like playa del carmen, so anything that built up is going to be way too much for me. Any other ideas? I was thinking perhaps Sayulita or Yelapa.