RE: Half Sandwich
Wouldn't surprise me a bit. They could be charging you extra for the convenience of not allowing you to eat a whole sandwich and stick to your diet (or splurge and buy those chips). During the Atkins craze plenty of places, even in the 'burbs, were charging a buck or more over the price of a sandwich for low-carb specials which were, essentially, a sandwich without bread.
So, if whole sandwich is 6.00+, you could probably charge 4.99 for a half. I wouldn't buy it, but someone might.