This is interesting to me. Is it BestBuy's policy to charge tax on the full retail value in every state? I live in Massachusetts and the law in this state is to charge the 6.25% sales tax on the full retail price always, it has been a law for quite a while but only really been enforced for the past couple of years. I also believe there are a few other states that require taxing at full price. I have heard that Radio Shack in Mass stores will sometimes "forget" to tax at the full retail price but that is them circumventing the law.
I also live 10 miles from New Hampshire which does not charge sales tax on anything so guess where I go to buy all my phones (and anything else for that matter)?