Good morning, here is another data point.
I found a Model y Demo for $45700 at Tesla location in Brandon Mississippi.
If you search on Waiting for Tesla, or the Tesla WWW site for Model Y inventory available for my zip code that price is ~$2000 less than any available Model Y in my state.
I am frugal, and I can fly to MS for $250 one way, and then use Uber to get to the Tesla location , so lets assume I would spend $500 for the trip.
Let me know where you can invest $500 and get an immediate $1500 payback for spending 2 perhaps 3 days traveling.
I managed to get an employee in the MS location sales on the line, very nice guy, put me on hold 2x times to speak to DMV experts (who had worked for Tesla since day 1), then his boss.
End result is NO, state laws limit the location to selling to folks in MS, or Louisiana, only.
He suggested perhaps they could ship the car to Devon Tesla in PA.
Logistics reply is Nope, we don't have any routes that go there, and pricing would be too high for one special trip.
Searching DMV in MS you find a "travel license plate" good for 7 days to facilitate buying car, and taking to another state. (From New Car dealers only apparently not Tesla)
Confirmed, No purchase from Texas, or Mississippi, so any good deals on Demo's in those states are impossible to purchase.
Conclusion so far, I can only buy from PA, and New Jersey, don't know yet about NY or Ohio or other states connected to PA
Will keep investigating and report here.