A Wisconsin man has pleaded guilty to ripping off a half-dozen retail stores in Iowa by pulling a switcheroo on UPC codes. Authorities say Jeremy Fishnick admitted using a home computer and printer to create Universal Product Codes.

The Lancaster, Wisconsin, man then took the codes he fudged into stores and stuck them on similar products that were much more expensive. Fishnick was able to buy a $900 welding outfit, for example, for just $150.

He went from store to store, sticking the bogus UPC codes on high-dollar items and having them ring up for a fraction of the cost. He reportedly duped Iowa stores out of $30,000 in goods in Anamosa, Cedar Rapids, Coralville, Dubuque, Maquoketa and Monticello and one store in Prairie du Chien, Wisconsin.