Went in for a check engine diagnosis for $39.99, which is cheap compared to what others have quoted me. They fixed the problem, and didn't charge me anything additional.
I did get a quote for brakes and even though they have $130 plastered all over the place, they tried to charge me $600! They claim that something needs to be replaced that I flat out don't believe.
If you're going in for something simple like an oil change, why not. Anything above that I would not trust.