Clarification: (God this seems difficult....LOL)
Plan A: Stay at Belize International and catch a 15 minute flight to San Pedro...$93US, Round trip.
Plan B: All of you leave in a cab ($15-$20US split between you, if you can get a van that will accomodate all 4 of you and all your luggage)...ride 30 minutes to Municipal airport...catch the next available flight...$46.50US, round trip...but then what is your return plan????? Going back to Municipal?...back in the cab?...back to International?
Good grief!!!! LOL Stick to Plan A...don't make it harder than it is....LOL You are trying to DE-stress, right?...not GET stressed!