I buy mine from Layne Labs. The quality is always good. Their site lists rodents with a weight range so following the 10- 15% rule for a young BP is easier to figure out.

A bag of 100 Med/Large pinkies is only $12.00 right now and is only about 4 x 8 inches and a couple inches thick. My kids have a couple small corn snakes very close to yours in size and they take two pinkies at each feeding. As they get a little bigger I will give them three until the bag is done, probably in the next month or so. I already have hoppers ready to go for them. A bag of 50 hoppers doesn't take up much room either.

A bag of 25 rat pups is maybe 10" x 12" and 2 -3 inches thick, so not very big. A bag of 25 pups is $30.00. I move my BP's into weanling rats when they get to be about 300+ grams again following the 10 - 15% rule. I feed my BP's every 5 days until they get to 500 grams and then move them up to every 7 days. You may want to get a bag of weanling rats as well to save on shipping later. 25 of them are $38.75. The bag of these is only slightly bigger than a bag of pups.

Don't worry about the percentage of the box is still empty message. Of course they want you to fill up a box, but I wouldn't keep so many that you run the risk of freezer burn after six or eight months of storage, especially with only two snakes. Maybe someone on here can advise how long they have kept their rodents fresh in the freezer. With 12 snakes I only plan for about a six month supply and then reorder.

While the shipping seems high, it is by far cheaper in the long run compared to buying rodents at local pet stores. Mice typically run $1 to $2, and I have seen rat pups as high as $3.50 in the pet stores near me.

Good luck!