You'll probably get hit with sales tax when you license it. At least I did when I brought my boat up from Oregon. At that time, unless you had owned the rig for more than I think 6 months, you got hit with tax on what the rig was worth.

Personally, I think that's fair. I paid tax on my trailer, which pays the bills around here. I kinda hope you pay tax on yours, so you pay your share, too.