Buttons pushed $5
Correct button pushed $50..
If you messed with it first $500
If some garage hack messed with it too,,, $1500
Base cost to run a shop with a storefront these days is about 85 to 95 an hour. So to make any money gotta charge about 30 on top of it. They don't know what you've done or what kind of chaos you have for them to deal with under the hood. I see guys dropping 10 to 20 K on a motor then a 600 dollar bill to get the engine tuned correctly?? Does not seem out of line to me.
Heck the guy I use for motor work charges about 2 grand + parts to assemble an engine with some mild machine work (Light touch up on heads guides etc, de-burr block if needed, basically do all the right stuff to maximize the engines performance, bal&blueprint, degree the cam etc...) The upside,, I've yet to see one of his motors die due to errors.. He typically spends about 14 hours per engine or more..