That sucks the guy wouldn't do it. That shop charged you about 3-3.5 hrs of labor to do the job at full rate. That is pretty standard rate around here anyways and about the correct amount of book time. Not sure how much the part cost but that seems reasonable to me as well. Things are expensive when you have to hire someone else to do the work. At least it's fixed, their's nothing worse than an exhaust leak I hate that.