It all depends on which 2 states the transactions are going to be made. I've bought trailers and motorcycles in Michigan, and Michigan law requires payment of Michigan sales tax at time of sale. If the Ohio tax is higher, the difference is paid to Ohio when you transfer to an Ohio title. We bought our current TT in Indiana, no Indiana sales tax paid, but full Ohio sales tax was paid when transferring to an Ohio title.
So the definitive answer is: It Depends.
I liked the idea of repayment of excess tax by a home state that never got a dime. Yeah, that'll happen.