No resales avail. for Belize yet. I would check the local alternatives such as Costa Maya Reef Resort and Banyan Bay including Grand Colony (nice!). Resales have advantages and disadvantages. Kinda like buying a new car and a used car - you usually get what you pay for.
Keep in mind a timeshare is not an investment but rather a vacation plan. Don't buy one to make money, rather to save money and enjoy a more luxurious vacation lifestyle.
Being said, Captain Morgan's is nice, good value for your money. I would look around first before making your choice in regards to vacation ownership.