This is what Google Maps is for. The reviews and stuff. Also, asking for a quote when you call the person.
I hungoveredly paid a guy $80 to pick the lock on my old drywall makeshift bedroom door. He didn't threaten me or call cops or anything, and the amount, while a lot, isn't $612. However, with sobriety and hindsight came the knowledge that the smart move would've been to take a hammer to the drywall.