While Pizza Hut and Papa Murphy's go with a hand-tossed heart-shaped pizza, Papa John's version comes with a crispy thin crust and is about the same size as a medium pizza.
While prices Papa John's thin-crust heart-shaped pizza may vary, it starts at $9.99 in my area. They're also running a deal where you can get a 1-topping heart-shaped pizza and a dessert for $15 and two 1-topping heart-shaped pizzas for $18 (deals may vary).
Photo via Papa John's.