do you ever use interlinetravel.com? they charge no fees unless within a certain time frame and have a great list of contracted resorts.
you've chosen some of the MOST expensive islands in the carib
do you have other options?
keep in mind when it says rain in CR, it's frequently 1-2 hrs in the afternoon or eve
same with other Central Am locations.
check with tripadvisor locals etc--hope you aren't forecasts from weather.com--BUNK