Demand for Rangers now is insane. I bought a 2011 this year and prices were going up month by month when I was looking. The new Rangers are much larger, basically full-sized.
Right now these old Rangers are very common. The main problem that takes them off the road, regardless of year, is rust, especially frame rust in areas that use liquid salt solution on roads in the winter. The one I bought had been undercoated and rustproofed, and it was a southeastern Virginia vehicle with little exposure to salt. That was the deal maker.
The Japanese compact trucks from before 1990 are scarce today and have been for years. Mechanically they were largely bulletproof, but many succumbed to bed rust because of the way the beds were constructed. Rust would begin around the seams. Cabs and frames were rust-prone over decades as well, but rust over a long time is true for lots of vehicles, not just trucks.
All the compact-truck manufacturers had diesel engines as options in the mid–1980s. Try to find one of those in any condition now; you can't.
What surprises me is how few people with compact trucks as personal vehicles (as opposed to business vehicles) got them undercoated and rustproofed when new. Another common sight is banged-up bodies. You expect this on a work truck, but some people beat up their personal trucks as well. That's hard to understand. Of course, hard driving, abuse, and lack of maintenance also kill lots of these trucks.
This stuff will make survivors in good condition collectible. I'm glad I bought my Ranger.