The Pizza Principle holds that there is a direct correlation between the rising cost of a plain slice in New York and a subway ride.

Times have changes since the principle was popularized; for one, the proliferation of 99 cent joints. So does it hold true? Here is amNewYork's highly unscientific survey of how much a plain slice costs:

Here is amNewYork's highly unscientific survey of how much a plain slice costs:

Famous Famiglia, midtown - $2.75

Caesar's Palace Pizza, UWS - $3

Little Italy Pizzeria & Deli, SoHo - $2.89

Frank's Express Pizza, Gramercy - $2

Vinnie's Pizzeria, Williamsburg - $2.50