Hi Rebecca,
Great news on your upcoming visit. I would check out GoDutchRealty.com. They deal in mostly home sales but do have rentals on their site.
Some other sources are Craigslist Costa Rica and vacation rental sites like VRBO.com. As in the U.S. Costa Rica Craigslist is buyer beware and don’t send any deposits without seeing the place. Vacation rental sites usually list stuff by the day or week, but if you contact the owner you can often get good deals if you talk to them about a long term lease. However you find a place you like always negotiate. You can usually get a reduction in rent, have them throw in utilities or cable/Internet, or maid service, that sort of thing.
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