Last month, the economics professor (Stacey Jones) and her business-statistics class at Seattle University compared prices for organic produce at the Broadway Farmers Market with that sold at the local QFC supermarket and Madison Market, one of several cooperatively owned grocery stores in the region.

To their surprise, the farmers market was slightly less expensive pound for pound, on average, for 15 items that included Fuji apples, red potatoes, baby carrots, spinach and salad mix.

"There's sort of a common perception that the farmers market is more expensive. A lot of people feel they're doing the farmers a favor," Jones said.

"I always assumed you pay a premium," said Daniel Robins, one of Jones' students, who regularly shops the West Seattle Farmers Market with his parents.