I think it is rather rude and a bit dishonest for people to not divulge their total fees upfront, an of course we should know to ask. But the normal person wouldn't know the questions to ask until they are burnt once like this, and then there still could be costs for walking up stairs or charge another service call if they need to go somewhere to use the bathroom and come back. THAT ISN'T A QUESTION I WOULD THINK TO ASK.
Another way to avoid a service call from your plumber is to make sure the outside faucets are turned off in the winter and make sure you disconnect the outside hoses. You need to shut the water off from the inside. Then, open the valve on the outside to let the water that’s in there drain out—you switch both of them to the opposite direction so one is always closed and one is always open. We have to fix tons of these in the spring mostly because people leave their outside hoses connected and they freeze up. The repair could cost $100-$200 or more. Another tip would be if you’re going away for any length of time, like on vacation, turn off your water. If on any of those days the temperature drops below freezing, have someone check in on your house. I’ve been called to homes where the family returned from vacation, and there was water flooding out from the front door.