Sean Piana handed another vendor a couple pieces of pizza for a lemonade and said, “That’s the going rate.”

The New Hampshire resident and Kaplin’s Pizza worker said many of the registered vendors who traveled from festival to festival on the same circuit would trade items with each other.

The economic theory of the open market was tested all weekend at the Wakarusa Music Festival, as vendors and patrons bought and bartered all weekend for all sorts of items.

Vendors, both registered and unregistered, sold wares throughout the park, including everything from food to illegal substances.

The festival’s registered vendors, consisting of corporate and local businesses, had the spots closest to the larger stages, which were on the southeast side of the park.

All registered vendor passes cost the same amount of money. The cost was $300 for the weekend, said Amanda Kapfer, Lawrence resident and partial owner of the Hot Tea clothing store.

Registered vendors were issued passes and had reserved areas to camp and park.

Kapfer and her associates took turns sleeping behind the shop.

“It was easier if one of us stayed behind so we didn’t have to pack everything up every day,” Kapfer said.

Some vendors had the luxury of campers that they converted into restaurants. Kaplin’s Pizza, from Louisberg, Pa., has modified campers turned into makeshift kitchens and showcases for pizza. Even the oven, which used to say Pizza Hut, was modified with a little duct tape, to read Pizza Kaplin’s.

Festival organizers designated specific areas for all registered vendors.

But many vendors were not registered and offered a more colorful and diverse lineup of items.

Most unregistered vendors paid for regular audience passes and paid to camp, then found a good place to set up their stores, said Austin Aser, Asheville, N. C., salesman.

“I don’t even own this store,” Aser said. “The guy who runs it just asked me if I wanted to work and I didn’t have anything else to do.”

Store fronts lined Shakedown Street, the main street through the camping area, using everything from the backs of vehicles to actual fabricated stands to hock wares at patrons who crossed by.

A few items that vendors sold included food, drinks of all varieties and glass pipes.

Much of the food items offered were easy to prepare. The grilled cheese sandwich found its zenith of popularity at the festival, being prepared on everything from hotplates to the palms of hands.

The other pervading item besides the grilled cheese was the glass pipe. Vendors sold them at prices that ranged from $30 to $100 depending on the complexity and craftsmanship of the pipe.

Drugs and other substances were also prevalent.

People would walk through the crowd discreetly asking “Mushrooms?” or “Acid?”

One particular “vendor” had the sales pitch on Sunday of “Happy Father’s Day buy some mushrooms.” He declined further comment.

The festival offered the patrons anything they wanted, Aser said.

“You can get good food and drink,” Aser said. “You can get anything to make your experience great.”