“He said he needed 150 of them. I said to him, ‘Are you out of your mind?’ ” recalled Felix Atlasman, the store’s owner.

Nothing in stock appealed to Mr. Tompkins, so Mr. Atlasman faxed over a few black-and-white pages from a catalog. Despite a brown-and-tan color scheme, model No. BY405-0786 caught Mr. Tompkins’s eye. A simple plastic webbed folding chair, it was the kind of thing “our grandmothers used to bring to the beach on the Jersey Shore,” he said. Sold, 150 at $19.99 apiece. (Later, the group bought several loungers in the same style, at $28.34 each.)

Meanwhile, an alliance security supervisor called up an old friend in Brooklyn: Matthew Pintchik, whose eponymous hardware store is a Park Slope staple.

“They didn’t want to spend a lot of money because clearly whatever was invested in these chairs would be disposed of,” Mr. Pintchik recalled in a telephone interview. He offered the alliance a discount on a line of Ace Hardware neon green and pink rubber chairs, 200 at $10.74 apiece.

The store has since received calls about whether the model is still available for purchase. “People liked the fact that they were sort of campy,” said Mr. Pintchik’s brother, Michael. “It’s too bad we didn’t know, otherwise we would have ordered them in bulk.” Despite the daily wear and tear, attrition has stayed low. After two weeks, only 25 of the nearly 400 chairs and loungers have been taken out of service. Fifteen others were reported stolen, and two more were picked off by an errant fire truck, according to Mr. Tompkins. (“It wasn’t going fast,” he added hastily.)

In some ways, the attention paid to the chairs reflects the more consequential civic debate at the heart of the Broadway project: what is the best use of public space?