$127.57

Hey, if you don't want to know, don't ask.

A tip is just that.
"Thanks, Great trip, get some dinner and flowers for the wife."
Depends on what you would like to give, and are comfortable giving. If they wanted a $50 tip, they should advertise a $50 higher price up front.
If the guide expects a tip give less than if they are humble.
Good guys = good tip.
Meat head = meatball tip. $0-10?

Remember, your best defense is to not repeat doing business with them again. (Meat Heads)