I bought a Starduster Too in 2005. As a plans built plane with relatively low total flying examples, the TN folks sent me a bill saying for me to pay 7% tax on sales price. The letter also said if I did not respond they would estimate the sales price at $12,500 and send me a bill. I waited for the bill.
When I moved my Cub, which I inherited as a non-flying project. I had owned it in Missouri (at my parents address) while I was finishing up my Army career. I eventually moved it to TN and changed address on registration and I got another bill from the state. They relented when I told them I had inherited the plane and could show it in the families ownership since 1969.
When I bought my Swift, it was registered in Oklahoma and I had to pay 3.25% sales tax. When I moved to TN and changed FAA registration, yep, another bill from the nice folks from the State of Tennessee. When I protested and showed I had paid sales tax in Oklahoma, they allowed me to deduct the difference between TN (7%) and OK (3.25%) taxes. So, I ended up paying more in taxes to TN just for moving than I did in Oklahoma where I bought and registered the plane.
It is a one time excise tax.
I just bought an RV-4 (and thus my presence here now) on which I'll get stuck paying taxes.
The good news is I know have an RV-4.
The bad news is I'll have to pay more taxes and sell my Swift.
Jim
N4WJ