I communicated with AIM about the sales tax. They sent me a link to Washington State Department of Revenue where it is clearly stated that an out of state seller can subscribe to a multi-state tax collection 'service'. So, it appears my WA state sales tax is legit if collected by AIM. My transfer FFL (Pantel Tactical) will only charge me for the transfer ($25). Josh Pantel is super easy to deal with so I am not concerned about the sales tax with him.

I also asked AIM to send me a 'clean' gun for whatever that's worth. I've been lucky buying used guns on-line. I have not (yet) received any gun that was not as described, in fact, I would say they have been equal to or better than described. One that comes to mind is a Browning BDA380 described as average was like-new.