When you bring your locks into a local locksmith shop near you, it will always cost less to rekey than to replace locks. But if you have a locksmith of Phoenix come out to your location, the savings will depend on how many locks you have.
When a locksmith goes to your location they will charge a service call to get their van and their equipment to your home. To save money, you have to rekey enough locks to make up this charge.
In our article How Much Does it Cost to Rekey a Home, you will find more details.