Well it seems to be based on Blue Book Value or some formula based on selling price, but not all TDs are home made so there is a bill of sale like any other RV.
Now for a home built what's its value? The cost of materials, an appraised value?
we pay a fee for the paper work and 7% sales tax when you transfer ownership, after that it's $20-$50 a year for registration renewal depending on the weight of the trailer.
Sorry for those that have to pay more, and need to have inspections done. It took a while to convince our loan agent that there was no such thing as trailer inspections here(car inspection is bad enough!).