$1-a-slice pizza at Rosa's in Center City

Mason Wartman was working in financial research on Wall Street not too long ago when he fell in love with New York's buck-a-slice pizzerias.

"I love the idea of a simple business," he said. "You're doing one thing and doing it well."

Wartman, a 2006 Germantown Academy graduate who studied business at Babson in Boston, said he did not want to see "eight, 10 dollar-pizza stores in Philly when I am 30 and say, 'That was my idea.' "

Age 30 is four years from now.

He has taken the step himself, relocating back to his hometown to open a $1-a-slice shop - Rosa's Fresh Pizza (25 S. 11th St., 215-815-1399) - near Thomas Jefferson University Hospital. It's named after his mother.

How simple is this: A bright, clean, utilitarian storefront on a dumpy block between Market and Chestnut. A counter with two plastic domes, each covering a hot-from-the-oven, 16-inch pie. They're $1 a slice - yes, $8 a pie. He offers a few toppings, such as pepperoni and sausage for 50 cents a slice more.

No salads, no hoagies, no cheesesteaks, no fries, no wings... You get the idea.

Pizzas emerge regularly from the oven. If they don't sell right away, they get tossed out, Wartman said.

Wartman found his star employee, Evan Robichaud, through a Craigslist ad. Wartman said Robichaud has good culinary skills. Through trial and error, they came up with a dough recipe. "The next day, we came back to replicate it and completely messed it up," Wartman said. "Then we did a lot of reading and saw how bakers do their math."

They shred mozzarella off large blocks and prepare the sauce with whole tomatoes, which are cheaper and more flavorful than the crushed variety.

How is buck-a-slice pizza? Pizzeria Vetri, Pizzeria Stella, DiMeo, Vecchia - the Neapolitan stars of Philly pizza - it is not. But as thin-crust, deck-oven pizza goes in Philly, it's quite respectable.

And it's a buck - come on.

Hours are 11 a.m. to 8 p.m. Sunday to Thursday, till 3 a.m. Friday and Saturday.