Possibly relevant recent article:

"Are restaurants like State Bird Provisions, which seems to resist simple economic analysis, the exception or the norm? And if they are the norm, is that because it is somehow self-defeating to raise prices even at booming restaurants? Or are chef proprietors a unique breed in the business world, immune to supply and demand and content to leave money on the table?"

http://priceonomics.com/why-dont-restaurants-charge-for-rese...