Yeah and for that seventy dollars from the tune-up it goes to paying for tools, training the mechanics, paying the mechanics, all the lil "spare" parts that get put on bikes, and covering some of the overhead, and the remaining couple dollars can be counted as profit. Trust me for the average person who hardly rides their bike, that seventy dollars is a deal by the time they have to buy their tools, lubes, rags, repair stand, some kind of training (whether books or clinics) and then the countless hours of tooling on the bike wasted cuz they have no idea what their doing. And dont forget the broken, stripped, cut too short parts/ pieces they have to rebuy cuz they mess it up...
Its like when people complain they we charge for what they consider "a simple tube install", so they buy the tube and go home to do it themselves, then come back 1/2 hour later with a "defective" tube thats been pinch flatted or gouged with a screwdriver, then finally end up buying another tube and a set of tire levers (which we recommend, but always get the funny lil comment of "ill just use a screwdriver)....