Because BP's are the most finicky eaters. lol
You may just have to start breeding rats, that or try and trade for something else.
Just a suggestion, look at reptile groups on facebook for your state, then put a post that you're looking for live rats. I'm sure you'll be able to find somebody nearby who breeds rats that may be closer. I did this with wanting to sell frozen feeders, and to help out local people and it's been working out great.