I was single for a long long time. As with car repairmen- if someone charges me for a new part, I want to see the NEW part and the OLD part when I pick it up. And that new part better be NEW.
When I first moved to OK, I went to the "viking" shop here. They charged me twice to fix the same problem, before letting me talk to the repairman, who didn't speak English (which is not an implication he didn't know what he was doing, though he didn't seem to) and then telling me that they would have to send it somewhere in Arkansas. WTF?
Never again. the place I go to has been in business for 35 years and the man who runs it knows his stuff.