Hi Steve ... and welcome to the board! Here are a few links for you to check out for cheaper accomodation on or across from the beach - you would have to contact them by email or phone to get a monthly rate for your dates (the price will also depend on your dates, ie before or after April 15th) and whether or not you require a kitchen or AC.

http://www.negril.com/jahbs/rooms.htm

http://www.negrilyoga.com/rates.php

http://www.jamaicalink.com/secrets/index-2.html

I am sure more boardies will respond with additional suggestions.