Pickup resale is hugely regional. I have friends across the country, I was shocked at how low they could pick up an 80's 90's Ford pickup with 300 I-6, 302 or 5.0L with only marginal rust. Around here in the NorthEast, people keep pickups on the road despite terrible rust problems, and a running pickup with terrible problems is $3K, inspected but ragged-out it's at least $5K. Madness.
As for mid-size... the Dakota got bigger and bigger, and lost the cool torsion bar front suspension and got taller with the awful strut front suspension... and sales dropped from a reliable 120,000 units per year to 20-25K per year until discontinued. If Detroit only would learn to keep making something the same size, or even a little smaller, or better fuel economy, but no, fuel economy on the last gen Dakota's was almost as bad as the same-engined Rams. Which is another problem, same engine. There was NO engineering going on there.
Full size pickups are a big market with big margins (high consumer costs, high profits for mfgs). Not everyone has the room-sized ego to drop $50-60K on something they use for groceries and commutes. There is room in the market for a good mid-size pickup. Not sure if the Colorado/Canyon is that pickup. We'll have to wait and see who gets it right with the next set of pickup introductions. The rewards are there. First and Second Gen Dakota's sold very well, always over 100K units a year, more then enough to keep them in production, until they screwed the pooch with the last-gen oversized monster that was larger than ealy full-sized pickups.
I really wanted a Commanche but they got discontinued so I got my first Dakota instead. That I-6 is a great engine. The Magnum V-6 needs heads every 100K miles, shoot there are 3 brands of aftermarket heads made for that engine. Always crack between the intake and exhaust valve, valves shift and they start burning oil through the heads big-time. The problem with mid-size pickups is we need a GOOD one.
OK, rant over.