If they get really bitchy, I'll hand 'em a pair of scissors. "Here, let's see what you can do!"
Got a good friend that's a fitter, fabricator, machinist, welder, millwright.
He used to bug me (usually after a couple of beers or 6!) about my labor rate. He'd say that he has got $50,000 in tools & machines, & charges $70/hr. out of his home shop. Whereas I've got $10,000 in machinery & tools & I charge $50/hr. How can I justify that?
Well, he wanted the interior of his '46 Chevy sedan delivery. I said sure, but I'll do a bit of a trade with you. I'll do your interior, you pay for materials, & while I'm doing that, there's a '62 T-Bird sitting there that needs an interior. You pull the seats out, mark 'em for layout, tear 'em down, cut 'em out, then lay out & cut out all the new material, so all I have to do is sew them up. I'll show you how to put the covers on. As I do one, you can be doing the other. He says, "sure!".
Three days later, 24 hours of work, & he finally finishes the job. I haven't started sewing any of it yet. He says,"Holy Crap! That's a bunch of work!"
I say, "Wake up call! What the 'F' do you think I do? Close my eyes & throw the materials at the vehicle, & the seats are covered?"
He never bugged me again about what I charge!
I guess you're right on the fact that I really don't know much about doing interior work. I mean, I put a couple pins in a piece of fabric once for my senior toga, but that's about it.
I don't do a lot of business with the public, but if someone off the street brings something into my shop and wants work on it, I charge a $55 an hour shop rate.