Now is a fair time to turn tables on the Missus and use the "female" ploy.
Rather than explaining how much you spent on fixing the beast try remembering ANY time the other half came back from a store, smile and say "But Honey, I saved XXX hundreds of dollars by doing this"
Then have your cost comparisons between dealer cost (+ labor) vs. PartsShop/FastLane. I can almost guarantee it will work, or your money back*.
*fine print - there are no guarantees!!
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.