VERONA, Wis. -- With the Thanksgiving holiday approaching this week and holiday shopping just around the corner, Wisconsin stores are charging more for products than their counterparts in Illinois.

The state's minimum markup law is most widely known when it comes to the price of gasoline, but it applies to more than just gas. Compared side to side, a Thanksgiving Day dinner at Walmart costs $5 more in Wisconsin than it does in Illinois, WISC-TV reported.

"The minimum markup law has been around for decades, and in Wisconsin it's gotten most attention around gasoline," said Deborah Mitchell, with the University of Wisconsin School of Business. "What most people don't know is it goes beyond just gasoline."

As a teacher of marketing, Mitchell is an expert in minimum markup law. She said the law dictates that stores in Wisconsin not sell goods for less than cost plus a minimum markup. That means Walmart must sell turkey in Wisconsin for 86 cents a pound instead of the 40 cents a pound in Illinois.

"It is frustrating to see the difference, definitely," said shopper Glenda Salmela. "I didn't realize there was that much of a markup."

Miller and Sons Grocery in Verona was around when the law went into effect in 1939. It's the kind of small business the law was designed to protect by preventing predatory pricing.

But shoppers said they wouldn't stop shopping at local stores like Miller and Sons if the law were changed.

"No, I support shopping locally just for the local economy, so it wouldn't change my opinion at all," said shopper Gene Mandarino.

"In reality, what happens is the consumer pays by having to pay higher prices and we have other laws that are used to police anyone who wants to engage in predatory pricing," said Mitchell.

There has been some discussion about overturning the law, but no specific plan to make it happen. Some Wisconsin stores could be hurt by the current law. Some residents blogged online that they were thinking about taking their Black Friday business across the border to save a few bucks.