The only 4.0's I could find in a single cab were mid and early 90's. I try and stay between 98 and 03
03 with the inline 4 was a good motor. Good all around service. I sold it to buy a Tacoma.. Ended up being a bad decision as I ran that Tacoma into a trailblazer, breaking my wrist.
I always bought rangers because they were more sensibly priced. I never paid over $3200 for a single cab, and even bought one for $900. But that was back when v8's were king and rangers were treated like go carts sitting in the back yard. I guess people are finally coming to their senses.. I noticed lately (really recent) rangers are starting to fall into the "Toyota" category as far as selling high. Also, when you look for them on Craigslist or local places, it's hard to find that (black, manual, 4x4, 4.0, extended cab, with the 02 honeycomb grille) ranger you're really wanting.. All the ones for sale are being sold for a reason, it feels like. You know what I mean?