(plural market prices)
In restaurant sense, particularly used for seafood, especially lobster and oysters, due to seasonality and volatile prices. Used to avoid having to update the menu as prices change, and also functions to avoid listing a particularly high price.
Using menu price is formally only only correct if the price of a dish changes because the price of ingredients changes (as for seafood), not if the price of the dish changes due to the composition changing (as on a cheese platter), for which as quoted (aq) should properly be used instead, as the more general term. However, as quoted is relatively little-used and unfamiliar, while market price is far more often used and more familiar.
market price - Legal Definition