I don't offer breakfast. This may sound harsh, but I don't see any reason why a parent cannot ensure their child has breakfast before they come. Maybe if I started really early in the am, like 6am, but otherwise, I don't. I manage to get my own kids fed and ready for their day before starting, so I don't think it's unreasonable to expect that of others.

If you don't provide breakfast, I wouldn't start now. If you do, I agree with $5 per child per day. This will account for the extra food, extra work and extra time.