Two things to note:
the online shopping world is all a scramble right now over reciprocal sales tax obligations depending on what states have agreements with each other. I am not current on the details but, it is something to consider for this discussion.
Here in Miami, after hurricane Andrew back in the early nineties, furniture manufactures from the Carolinas were selling semi truck loads on the road side trying to get that insurance cash. No sales tax was charged on these cash deals. The state went back to the weigh in records other things and persued the buyers and sellers. I'm not sure how far this went, but it had everyone freaked out.