Warning: a customer quoted me $40 for a derailleur tune and I almost laughed in his face
He told me the big box on Route 9 does full drivetrain work for that price, so I asked him what they actually adjust, and he couldn't name one thing, which tells me they're just wiping the chain and turning barrel adjusters, and I'm done pretending that's the same job we do.
Keeps the price real by asking the guy what they actually do, but I don't buy that a shop like that is only wiping chains. A $40 tune at a big box is probably a real tune for the kind of rider who walks in there, and a lot of people just need their shifting fixed so it stops skipping. The gap between $40 and whatever you charge is mostly about how deep you go and the time it takes, not whether the other guy is a hack. Explain what the extra money buys and let the work speak for itself instead of laughing at the quote.