For the details, I tend to want more than just things that apply to that one adventure. I feel ripped off if once I've played the adventure once, I no longer have any real use for the book. In fairness, I also feel ripped off if I buy a book (like a novel), read it, and don't want to put it on a shelf and read it again a few years later. I'm pretty sure I'm nowhere near the norm in that.
Maps.... maps are a judgment call depending on what you want the map to do. If you want the players to know what they'd see if they were looking down from an aircraft or right there at the scene, then accuracy is everything, and yes you'll want full color. But would the characters ever have such knowledge under any circumstances? Right there at the scene, sure, but the bird's eye view.... really? If not, then you can immerse them in the setting as well or better by, rather than drawing a map whose accuracy rivals that of a satellite photo, drawing a map whose accuracy rivals the kind of map you could expect typical people in the area to have. In other words, hand drawn B&W.
The third one is purely subjective according to how much stuff the player wants for his money, how much he's willing to pay to get it, and how much work (and thus cost) the authors/designers are willing to put into a single product which may or may not produce a return.
Me personally, I like all of them, they serve different purposes and which one I'll want varies with which purpose I'm trying to find material for.
