Huatulco is a beautiful, safe, friendly area. But like many tourist areas, there are those who are anxious to take advantage of unfamiliarity of the area.
That happened to us (& to others we have learned) in Playa Entrega. We were clobbered beyond reasonable on our lunch. Don't really know how the bill totaled what it did, but we walked away from the restaurant Cielito Lindo $75-$80 USD lighter in the wallet. We didn't order anything crazy (nor a lot of anything). Everywhere else we have paid no more than $30 USD for a similar order.
I have heard of others being charged $150 pesos for a sombrilla even tho they ate at the establishment. Others have been told they were being taken to a private island by the taxi driver and they end up at Playa Entrega after paying through the teeth to arrive at this "island".
We won't return ever to Playa Entrega. However, others may have had good experiences and feel differently. Just wanted to pass on our cautionary tale so that others can be forewarned. There are a number of wonderful beaches and it is not necessary to risk La Entrega in my view. Playa Santa Cruz is wonderful - flat, calm, very swimmable with many restaurants and bars to enjoy. Beachside restaurants are almost always more expensive - but $75 US for lunch for 2 is crazy.
On the other hand, the restaurant Terra-Cotta is the bargain and find of the century. Very close to church in Crucecita, this is the restaurant for the Hotel Los Arcos. Wonderful, wonderful menu & food. Lovely restaurant (with AC), very reasonable prices all served by friendly, attentive waiters. Don't fail to get some of their ice cream. !Maravilloso!