that's what i'd have thought, but i could be way off. I'm guessing it's more marketing- much like with the cheapo cr@ppy trems on cheaper guitars- they could put the neck profile everyone wants on the cheaper guitars, but then far fewer people would buy the more expensive guitars with the bigger profit margins.
Obviously things like rolled fingerboard edges etc. will cost more, and maybe some of the fancier neck profiles do involve more work. :?
EDIT: cheap basswood is horrible, good quality basswood is nice. Though bear in mind it doesn't sound the same as mahogany, alder, etc. etc. It doesn't really sound like the "vintage" wood does.