Answering from Louisville, KY, but hope this helps. My best resource for both alfalfa pellets and soybean meal has been a local pet supply company ~ Feeder's Supply. They are always stocked with the alfalfa, but are kind enough to order the SBM for me ~ usually about $20 for 50# bag. I would think that any place that carries rabbit food would be able to order the other for you. Now if I could only find a good source for 50# bags of plain old corn meal !

Tractor supply has Alfalfa pellets.... and you can get soybean meal up north of Hamilton at Brubaker Grain & Chemical. Call ahead to check the price since it changes. They are a good company that I have been going to for a hand full of years for grain/fertilizer for the lawn and garden. It would be a hike up there, but you can get enough for the year in one swing

Try an ag co-op or feedmill. You'll get the best prices in one of these places.