Perhaps if the plumber is called first, he/they might give a ballpark figure as to what the costs "might" be. Otherwise, once they come out, (just like a refrigerator repair man) he's going charge you a service fee regardless if he doesn't even touch a thing.
Correct, those days are long gone, where a plumber charges $20 to put in a faucet.
A few weeks ago, my father who lives in Chicago, had to call a plumber to fix 3 leaking faucets. Two small gaskets, and one replacement cartridge later, the bill was $221.00. $21 in parts, and $200 in Labor for 2 hours labor.
The price the original poster mentioned doesn't sound too out of line, but agreed, he probably charged her the time while he ate her lunch. Maybe she should've handed him a bill for lunch, $30! :-) Mark