Florida here: Car and truck tags are ~$40/year for a standard, non-personalized, non-special edition (we have a whole variety of specialized tags for everything from state universities to animal lovers, a portion of the cost from each tag goes to those groups). It goes up slightly based on size/weight of vehicle. Boat registration, depending on size of boat, are ~$40/yr for a small 14-17' boat. Trailer tags also vary by weight. Boat trailers are ~ $35, my 16' car hauler was around $65 and my 20' gooseneck cattle trailer was around $75.
For my F250, F150, Expedition and TJ, 14' boat & trailer, 16' boat & trailer, 16' car hauler, 20' gooseneck I am right around $650/year. Three of the vehicles have personalized/specialized tags, the rest are normal.
FL does get a one-time premium for any new registrations where you are adding a new tag and that is ~ $500-600 as I recall from about 6 years ago (last time I added a car to the fleet). Otherwise there is a nominal fee (like $50 or so if you are just transferring a tag from one vehicle to another.