Where do you buy your rats? That's really expensive for med rats. They'e $3 here and I thought that was over-priced.
I feed Dovah once a week if he's willing to take it. He's also on the small size of med rats.
If he doesn't take it, I wait until his next feeding day. He's on a strike right now, the jerk. lol
Snakes don't grow by their enclosure, they will continue to grow to their max size no matter what you do. You could keep them in a 10 gallon and they would still reach their full adult size(never keep an adult bp in a 10 gal)
If you want a smaller snake, perhaps you should look at other species.