It's a bit different up here, there are no private companies typically, so you buy direct from the government, at 250-300k KM(not miles). Most are Crestline, built in Saskatchewan, which are very nicely built, albeit a bit narrower(they don't go right out to the edges of the dual tires, and have mostly welded bodies). 7.3L ford turbo diesels.
Low hours get a premium price(4000 hours is not uncommon, I took one with 7000 hours, which saved me about 2000$ buying it, which is the same cost as another cutaway e350, or a good low miles(and very low hours) engine and transmission from the same era.
I shopped carefully, bought at auction at the time of year that no one was going to be shopping much(January 2nd), and got one with an ad that sounded bad, but I researched the history of the van based on it's unit number and decals.
Paid 3100$. 260k KM, 7000 hours on the engine. Minimal rust. Minor issues to fix up(cracked fender etc).
They have less value on the used market because we don't have so many private companies. As a result you see them turned into work trucks and campers and similar around here.
I made sure to pick one that was from a relatively low stress position for a large portion of it's life, so it seemed less likely to be thrashed.
Runs well so far.