If you buy a new vehicle out of state from a dealer, are you expected to pay sales in CO, the other state, or both?

I found an identical vehicle in a lower income state that is about 15% below MSRP while the one in CO is 10% above MSRP and the in-state dealer won't budge to match. The out of state dealer said thier price is for anyone, but the person I talked to wasn't sure of the taxes and the finance guy was busy.

So to save quite a bit, a flight and taxi ride to that dealer would be well worth it.