My son has 9 snakes. We have always feed live. One of our BP will only eat in the dark. Well we just had a rat do an number on him before he killed it. NO MORE LIVE feeding here. We are in the process of switching all my son's snakes over to pre-killed food. Watching your snake hit and kill it's food can be axciting and amazing but for us it is no longer worth our pets health. Rats and inflict a lot more damage than mice and your snakes will one day be large enough that they need larger food. I know everyone one on here has a different opinion on this subject, but it is something you may want to think about. Should you ever want to change to pre-killed, the sooner you switch over, the easier it will be.
As for your mice situation, I would get the phone book out and call all of your small independent pet shops. They ususally buy mice from independent customers living in the area of their shops. Also remember that as long as your snakes are in good health, BP can go for a long time without food. One of ours just went 5 months without eating and I just talked to a man that has a 23 yr old BP that he hatched and has raised. This snake only eats 4-5 times per year and has gone for over one year without eating. So, do not worry if you can not find food right away. Call your small pet shops. I am sure you will find a food source.
Teej