My experience is limited to NorthWest PR, I live in Rincon, areas near here are Isabela, Aguada, Aguadilla, all with access to beaches. Rent is relatively cheap here. A decent 2 bedroom can go for $500, maybe less or more. I have a great deal of $300 (electric and water included) close to beaches and with a view of the ocean and gorgeous sunsets). Yes clasificados is one source, but limited in my opinion, and some people have found stuff on craigslist. Numerous places for rent are not listed in either of those sites. They are found by talking to people, knocking on doors, and driving about. Some examples. I found my place by chatting with surfers on the beach. A couple I know found theirs while driving around - a house was for sale - they stopped and asked if they could rent and yes they could (2 bedroom for $300) - houses for sale can hang like that for years. My point is - if online searches get you nowhere then put your boots on the ground and look. You can also then determine if you like the neighborhood and area.