A lot depends on your resources for cooking. A naked fattie, egg disk and english muffin are terrific, but, you need a stove and flat top. Yes, I said egg disk. My favorite is a biscuit with a slice of fatty and cheese in it.
In terms of charge, you have to determine food costs, unless you are donating the food as well. People are used to paying around $3.50 to $4 for a breakfast sandwich, you can sit in that neighborhood too and make some sales.
Egg disks-take a bunch of eggs, one dozen per 18 sandwiches or so, slightly blend by whisk. Pour into muffin top pan and bake until set. Let cook, stack once cooled and chill. You can then reheat these, even on a grill, in minutes, pop on a slice of fatty and some cheese, a muffin, Portuguese bread roll or biscuit and you are go.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"perhaps...but then again...maybe not..."