In general, it seems "Westernized" restaurants are always so much more expensive than ethnic eats. Whether these restaurants serve American/European food or whether they offer a "Western" take on Asian or Latin food, it seems that there is a universal minimum of how much each person has to spend at these types of places. In an ethnic place, it is easy to get out spending less than $20 and feeling full. Nowadays, it's very difficult to get out of a gentrified type restaurant without spending at least $30 a person and that's with choosing items in the menu that are hopefully filling.
The first thing people would say is different would be the atmosphere. It costs money to have some sort of atmosphere. Next thing would be marketing costs. Then that leaves rent which may be more expensive if these restaurants are in prime neighborhoods, but doesn't explain restaurants in less gentrified areas of Broooklyn or Queens. One could argue that food quality may be slightly better too. In terms of wages, these restaurants pay the same minimum too and just have servers count on tips. Considering that in ethnic places, servers don't get as much in tips, it could even be that they need to get paid more wages.
With all these differences, though, it is still hard to justify the significant cost difference. Is it just because people are willing to pay more for these places? Is it because owners of "Westernized" restaurants demand a higher net income for themselves than owners of ethnic places?
I was just thinking too that a factor could be turnover in that places with nicer atmosphere experience a lower turnover. Can this problem be solved then by offering the same prices as ethnic places with the same nice atmosphere but just setting a one-hour time limit for diners?