Well said AW.... I like what DVS said about behavioral science as well.
The one thing I would say however is that with modern day society's obsession with technology and the internet, everybody likes to think they are ____ savvy. "Oh that landscaper isn't going to fool me! I can look up the cost of those pavers at the touch of a keyboard!"
And really, that is the ONLY thing I see people griping about in terms of a break-down. Materials.. And let's be honest, it's always been that way. Plumbers, electricians, carpenters, ...... You name it... Tradesmen are always getting second guessed on the price of materials....