No. If you didn't buy the skis or bindings or boots from them, or your not a regular customer there, then no, that's pretty standard.
If you bought something from them, then yeah, that's a little steep. If you're a regular customer that is loyal to the shop, then yes, probably then also it would be steep.
You have to look at it from the shop's point of view. They aren't making much money off you, and in turn you're getting piece of mind that your bindings are mounted correctly. I know some shops that charge $75 for walk in customers.
Overall, 50 is pretty reasonable. I bet buying something cheap like a movie and talking to them about skiing for a while would bring that down tho, if they're a cool shop that is.