Pitt, a live rat the right size for an adult bp is 7-10 bucks in my area, unless I was to get them at the local show once a month, which isn't entirely local since it's an hour away. Hence having to breed my own.
Now to the point of this thread, I have a couple individuals that will not take multiple prey items, so if they were stuck on mice it would be a real issue getting enough food in them.