Re-key or new locks for your home
If your state requires licensing. Make a copy of the locksmith ID. This person can easily make extra keys for your home and sell them to a criminal.
If no license is required in your state. I suggest you get as much info on the company/individual you are dealing with.
This type of job is hard to give a flat rate as too many variables are involved. To get the most accurate price, send a picture of the lock(s) that need to be re-key. This will give locksmith an idea of part cost and time.