Don't stop in Georgia -- I dunno how they price trailer tags, but their automobile tags are based on Blue Book values every year, like many states do.
Washington got so bad that just a few years ago, there was a citizen's initiative that ripped the guts out of the old system and went to much smaller, and reasonable, amounts (Problem there was the onerous registration
fees were part of the revenues supporting a large number of things like the ferry system and the state parks, so there has been a lot of budgetary scrambling!).
Also, keep your original documents on how much sales tax was paid when acquiring a vehicle or trailer because if you move to a new state they may want the difference between the tax rate for the old state and new state, depending on the laws in the new state.
For FullTimers in BulgeMobile motor homes or trailers with large, expensive tugs, this can be a large sum of money so it pays to do one's homework.