logistics of buying a van in a different state?

[B and C]

Are you going to get a driver's license from there too? You might want them to be from the same state if you get stopped.

[Kaylee]

Brian, I did consider that, but for now I want to retain my existing "domicile" state.
South Dakota has a special provision for people like me who are true Nomads, but already have a domicile state and for whatever reason have difficulty registering our vehicles in our putative domicile state (in my case, evil county employee refused to renew mine).
See the SD gov link I posted above (has some interesting legal reference docs).

Now, a keyboard review (i.e. not tablet):
The place was busy, but there was only one person ahead of me. Remarkably fast wait time!

The guy I got was fully versed in non-resident registration.
First thing he asked for was Title and SD driver's license, I explained I wanted to do the non-resident registration, he started to ask a question and I quickly said I'm a Nomad, he stopped, nodded that he grokked it, and we proceeded.

I was afraid they would require me to use a mail forwarding service.
Nope!
GypsyDogs and I ended up putting my existing USPS PO box on the bill of sale, and he merely confirmed that's what I wanted to use. He wanted a phone number, I politely declined and I offered an email address which he accepted without hassle.
(It's amazing how many orgs insist on getting a phone number!)

I was expecting to have to fill out a ton of forms, but I only had to fill out the non-resident affidavit (I suspect he could have printed it if I hadn't already done so).
He filled out everything on his computer, printed stuff, and walked me thru signing it.

After I left Oregon, I realized we hadn't put the price on the Bill of Sale, and I verbally told him how much I paid & that it was above book because it was a conversion. He said he'd look up book value, and use the lower of the two. That saved me a nice amount.

After a stressful overnight (unexpected snowstorm caused me to stay at a rural exit turnaround) and morning (I made more newbie classic van starting/etc mistakes), I was very frazzled, and he made it low stress & smooth.

Bonus:  I saw a mug with a Star Trek symbol beside his desk, asked him if he was a Star Trek fan, he flashed the Vulcan sign, I flashed it back.

NOTE:  if you do this, bring cash or an approved money order.  They have strict limits on how non-residents can pay.

I feel like I'm finally a Legit Van Dweller!

[B and C]

Congratulations! That does sound really simple.