When I first moved to Belize, I rented a condo at Royal Palms for 30 days and I think it was $800 USD for the month. Kitchen, showers, I was next to the pool, and its a beachfront property. Now I live at Royal Palms and I see Brittany from Belize Management bringing people here all the time. You can contact her here:
http://belizemanagement.com Hope that helps.