The carpenter or plumber analogy is a good one. Just ask someone if they had a carpenter do some work on their house and he worked for 5 full days with a materials cost of $200, how much would they expect that job to cost them? $600? $800? $1000?
I figure that a very simple queen sized quilt top, I mean REALLY simply like Yellow Brick Road or something like that, could be done in 3 days. Then another two days to quilt (if you have a longarm) and bind.
A Quilt-In-A-Day pattern is probably based on a smaller size and who really gets one of those done in a day? :P