I would go for the best deal, and if I avoid sales tax that is a bonus. I live in CA, and believe me, we pay more than our fair share of taxes. I go to great lengths to avoid sales tax, but that is only because of this state's love affair with high taxes. The gas/car tax increase hit me for about $80 a month, so in response I cancelled cable tv and don't miss it.
I have bought several high dollar bikes in state though because the deal was good enough to justify to me. In fact, all three bikes in my sig were purchased locally, as well as a Trance Advanced 2 and a Pine Mountain that I sold. Perhaps the local bike stores are selling bikes to buyers out of state who avoid their local sales tax?
Unless you like the local bike way more, then a year from now you won't remember or care how much you paid.
Gman