All shops are very different, I know of a car thats been well set up for 7 years,Needed a bit of a tune so he went to a well knowen shop for a tune only to be told his ECU was no good even tho it had been for so long. He was sold a new ECU and the drive away price was over $7000.
The guy drove down the road and ran out of fuel,Got some more and told the tuner the car ran badly and had run out of fuel only to be told his car was not tune as it had no Fuel. 7K drive away with no tune and no fuel is rough and worse still he now finds he has no other tuner options.
Make sure you know what you are getting before you leave your cars anywhere.