I’m going to guess that the higher fee for a VHF Marine radio is for a land based station. The lower fee was for licenses which are supposed to be used for marine purposes. I've never heard of Marine Channels being sold.
Hams are a totally different situation which requires an examination for a license and more expensive equipment and many regulations. If not done properly I would not be happy if a ham operator was next house over interfering with TV and other electronic equipment which can happen. They operate at high wattage and are suppose to be used for long range. They are not really suitable for this discussion. The other long range radio which I had a license for is Single Side Band. This is another long range radio not to be used for short range, you need to be licensed and is highly regulated with much regulated frequencies. This radio is also intended for Marine use.
The good thing about CB is that it doesn’t interfere too much with other electronics, is short range and simple to operate.
I’ve seen 2 way radios being used on AC I believe and that is probably the best solution for use between people who want to stay in contact with minimum regulation. I do not know what the regulations for this type are in Belize. They are next to nothing in the USA.