That would make sense...but often times it depends on the moods of the customs officers. I know that departing Belize if you take something with you that you plan on bringing back (one time for work I brought two laptops to the States from Belize) and don't want to pay duty on it, you can put an entry in a ledger aka notebook that the customs officers have. Then when you enter Belize if they try to charge you duty on that item you can show them in the notebook that you originated in Belize with it. Not sure if there is a similar process on the in and out of Belize though. But I've never had any issues.

BelizeComputerGuy@Gmail.com