Starbucks' prices vary considerably by location. At a Starbucks in Manhattan, ordering a butter croissant costs $4.45, while two of the breakfast sandwiches cost $5.45, and four cost $6.45.

Dunkin' Donuts will begin selling a combination croissant-donut early next month, an official said on Monday, as the coffee shop chain follows a popular pastry hybrid that has drawn hordes to a ...