PHOENIX -- A hidden camera sting found locksmiths could be charging hundreds of dollars more than their services are worth.

Using a central Phoenix home as a test site, 5 Investigates rigged the home’s front door with a common lock problem that causes the key to spin without engaging the lock.

The problem can be fixed with a part that costs $1, with repair charges and service fees costing between $80 and $90.

However, after calling four different locksmiths to fix the lock and re-key another, 5 Investigates received estimates that were significantly higher.

One estimate was $175 and another $284.

5 Investigates was also told by one locksmith that the lock wasn’t replaceable and by another that he didn’t have the part to repair the lock.

Only one of the four locksmiths said he could repair the lock; he charged $93.

An insider in the business said when it comes to finding a fair locksmith to do a job, it can be a hit or miss experience.

"You'll get some very fair locksmiths that'll come out and give you a fair price for what they are about to do and other locksmiths will come out and tell you that all your hardware needs to be replaced," said the insider.

The insider also revealed some of the tricks he used to use to scam customers out of more money.

"I removed the lock that wasn't really broken, put on a lock that was slightly used - that had come from another job. Told the customer that everything was fixed, charged them $325 and left," the insider said.

5 Investigates cautions if a door lock is broken, don’t assume a new lock is needed.

Also, call several locksmiths; they all offer free estimates.

Shopping around could save $200 or more.