It is a goods tax free zone for non-Belizeans that do not reside (or are on vacation) in Belize. This a to stimulate foreign trade and receive foreign currency.

If you shop in the free trade zone you should have to enter and exit via Mexico. When you renter Belize you would be expected to pay import taxes, gst and/or stamp duty on the items you bring into the country.
And departure taxes would be applicable.

A & B would seem to be somewhat mutually exclusive. If it is for me (a non-Belizean & on vacation) then making me go into & out of Mexico and pay import, gst/stamp duty, and departure taxes would limit the amount of trade and foreign currency I could offer up I imagine. Are the deal that good?

I guess I'm learning such situations are not "strange" in Belize.

Thanks very much for the info & would love to hear more about the Zone. Or traveling to Mexico for shopping and stocking up.