For anyone unaware, there is a process called "Regulariziation" that, according to a senior official in Marsh Harbour named "Frisco", is far more affordable than your entry and extension of a temporary cruising
permit.
I haven't looked into what it is specifically, but when we spoke in May of 2024 at the Marsh Harbour offices, he said he doesn't understand "why people don't regularize if they're staying longer than 3 months". His words.
Again, he was a senior official and his knowledge and vocabulary on all things
customs gave me no reason to doubt him. Certainly worth a call to the Marsh Harbour office to speak with Frisco, in my opinion.