The comment a few posts back about Wingnut Wings got me thinking...to me there's a very definite "sweet spot", size-wise, for kits. Namely a 9-12" wingspan. This encompasses most non-tiny WWII fighters in 1/48, and the tiny ones in 1/32. It also encompasses a good many 1/32 WWI kits and a large number of 1/72 bombers and other large craft.
Much smaller than that and you start verging into tininess, much larger and you get into the big honkers (a 1/32 P-47 has a 15" wingspan). To me, the decision to venture above that 12" wingspan is reserved for flat-out awesome aircraft. If I'm going to chew up that kind of space, I want to do it with an awesome kit and an awesome subject.
Maybe that's why I'm willing to pay more for 1/32 kits? I recognize that they are, in effect, the flagships of my collection, and am willing to dump resources into them accordingly.