ImUrPropofol
Registered
I think $0 (i.e. don't tip) is a valid response to the OP's question of "how much?" and the subsequent tip v. don't tip is pertinent discussion immediately pertaining to "how much?". I agree with TM, I never tipped my kindergarten, elementary, high school, or college professors. I didn't tip my flight school instructor. I sure as hell didn't tip the attending physicians during residency. All were instructors of some kind. I've used the same dive instructor for all classes and he still seems to like me even though I've never tipped him either.