Quoted from KingPinGames:

This has definitely been on my mind lately. I have lots of customers in different states, mainly for tax reasons, but also because we have built a relationship. The way I understood the law was "if I (the seller) had a physical presence in the same state as you (the buyer) then I was required to collect the sales tax. On the other hand, if you (the buyer) were located in a different state then it was up to you to pay the tax. It's not that you never had to pay the tax, it was that I just never had to collect it.
Now, under the new laws, I'm am a glorified tax collector for the government. What does this mean for me as a distributor? Let me ask this instead. Let's say I make the 18 hour drive one way from my office to texas pinball fest. What advantages does a texas resident have to buy from me instead of from their local distributor? Other than offering extended warranties and exclusive stories about the superstar jjp designer?
I can see this new tax collection law increasing my local sales as now I am on the same price level as guys from out of state, but I can't see a reason (other than personal) for making the business journey to far away shows. I will probably still make the trip to tpf because I like the show and they (dallas) do not have a local JJP/Spooky distributor, but (as always) I encourage everyone to buy locally to support local dealers.
I ask the pinside crowd this. Would you still continue to buy from and out of state dealer if they had to collect sales tax from you (and charge a higher shipping rate)? I included the high shipping since shipping one game states away cost more than shipping a dozen games to my office where "local" buyers can pick them up? I have lot of pinball friends in lots of other states, but I would not blame any of them for choosing to buy locally if all else was equal.
Lots to think about in 2019.