I've seen some good used deals, the one we looked at last night is attractively priced and would work with my truck on paper, in real life I think it would be stretching it. New MSRP are way high but it seems most dealers knock off a decent chunk right away, that still doesn't make them cheap and they drop another 20-30% in value as soon as they leave the lot. A package deal with a tow rig & camper would be attractive and I could slash some of that investment by selling my current truck but I'm not seeing any of those.
The interior quality of just about everything we've looked at seems suspect, Wood isn't wood, it's like some kind of foam board with a vinyl wrap which is fine until it isn't. I know if we buy used and I start fixing little things as the kids tear them up, I'm going to use real wood and that's going to add a little more weight. The mechanicals I'm comfortable with too, I don't mind maintaining things, I'd just rather avoid having to be repairing a bunch of stuff due to poor initial quality.
Regarding size, the 25' we looked at last night would be about it on the lower end and still be comfortable. I'm going to another dealership today to see what they have, the four bunk beds in the back is one thing we know we really want and there's options out there, just not a whole bunch of them.