That's how Stu Auerbach got started.
Returning from Korea in the 50's where he had experience with Army mine detectors, he picked up a surplus detector and took it to our Florida beaches. He began finding all sorts of coins and jewelry. No competition back in the 50's. Others saw what he was doing and asked him where he got the detector. He said he just happened to have a second one in the trunk of his car that he would be willing to sell.
Stu immediately saw a marketable opportunity in selling metal detectors and thus Kellyco was born.