SMB West just runs the Nevada store as a little place to conduct sales in a state with lower sales tax. (They do charge a shipping fee though.) The vans are still upfitted in Fresno. If you take delivery in Fresno, you pay full CA sales tax, which ain't cheap. If you take delivery in NV, you pay considerably less tax. Regardless of which place you take delivery, you then have to deal with your own state of registration. Here in WA, we have no state income tax, but sales tax is higher than CA. If I take delivery in CA, I pay CA tax. Upon registration in WA, I subtract what CA tax was from what WA tax is and pay the difference between the two to WA.
Too bad SMB-W didn't set up this little sales office in OR, which has no sales tax. Then buyers would pay no sales tax at all at the point of purchase and would only have to deal with the state in which they register the vehicle.
A fair number of people from other states set up a Limited Liability Corporation (LLC) in Montana and register their motorhomes as a business expense in that state. There are lawyers there who will do this for you and even pick up and mail your plates to you, no matter where you actually live. CA has been cracking down on its residents who do this.