Well, there is no official book or a trick to find if a place is generally expensive, however, I have come to a very generally conclusion that if the price of tea is high on the menu, then every dish would be expensive too.
The reason why I came uo with this conclusion is, coffee is served in many names and combinations and could be served at highest prices, however tea has its own standard taste and ways of serving, hence there is not alot that could be done to increase the price.
So if the tea is expensive for no reason, the food is also going to be quite expensive.