This is where we take the existing lock off the door and change the pins inside the lock so that the old key won't work anymore and you will get a totally new key. Then we put the lock back on the door. The only reason you would need to replace the locks is if they were worn out, or you just don't like the look of them.
Pricing - most all locksmiths price the same way and that is they charge per cylinder, or per keyhole. Both terms mean the same thing. A doorknob will have 1 cyl.- but some deadbolts have 2 cyl's. one keyhole on the inside and one on the outside. So you must count 2 cyl's for those locks that need a key to lock it from the inside, as well as the outside. Keep this in mind when adding up the number of cyl's. before calling for a price.
NOTE "You must count every keyhole inside and outside on every lock and every door that you want to have changed."