HAH I just went through all of this with Disabled Explorers....
California sales tax is higher than Arizona so SMB West delivered the van to SEMA in Las Vegas where I offically took delivery. They place a temp reg tag on it so I could drive home to Arizona.
Arizona did look to see if I had paid the CA tax and only since I didn't Arizona ask Disabled Explorers to pay 5.6% sales tax along with registration fees...still less than California would have charged and since it comes out of my overtime work at the hospital I was very very happy
I was lucky enough to visit the SMB West factory a number of times during the build and hang with Alan at SEMA so I don't feel I missed out on any new owner orientation that would otherwise happen when a person picks up their new rig.
It really comes down to money vs time/hassle....
in your case James there is a real benefit to arriving at SMB West in the morning, spending some time getting to know your rig and it's systems and camping close to Fresno the first night just in case there is anything to catch before starting a long trek east. I don't know the math you face well enough to say if that is worth the tax difference.
There is also the issue of AZ annual reg cost vs NY...these do get classed as RV's so that could make a difference even if you pay the tax in Cali.
Vegas is only like 6hrs from Fresno and I am pretty sure the guy they use to deliver the vans is a regular at it so he could give you the full tour and if needed you aren't that far from Fresno...again cash vs time/hassle.
If it was me, there is just something fun about being at the factory, meeting Alan, Jonathan, Liz and everyone that I enjoy. Of course you will see Alan & some of them at the Overland Expo...but that new rig feeling
Have I clouded the issue enough yet with my rambling?