I guess that depends on how you define expensive-we thought it was much cheaper than hawaii-some areas-particularly the Condado area of San Juan are very upscale.
OP start with
www.gotopuertorico.com. I think the hotels you are looking for fall under the classification of paradors. I have been there twice-once about 5 years ago we said in San Juan for a week before a cruise we took. We went to the Rain Forest which was amazing-Lunquillo Beach which is quiet nice-on a par with some other very nice beaches we have been to else where, toured Barcardi and drove along the northern coast to Rincon on the west end of the island-thru small towns and neighborhoods-that was not upscale at all-but like driving thru any area of small towns-and some very poor areas. its is a very beautiful place-and eat in small local resturants-puerto rican food is awesome. I dont remember the names of the "out of the way" places we ate-we just stopped where there were alot of cars-we both read spanish and speak enough to order food so we were not concerned about that-the two places i do remember were the Parrot Club in Old San Juan-its Cuban food-and omg its good-and Yerba Buena in Condado-i had the most amazing chicken and yucca dish ever.