They can charge more for the pelleted kind.
It runs smoother through most hobbyist spreaders.
If you only need a small amount, you could grind it up.
I would look for "feed stores" or "farmers' co-ops". And if you go in person, be sure to ask for "a big bag from the warehouse". Usually you can pay the same amount of money for a 50 pound bag, or a one quart Yuppie-consumer-rip-off-size with colorful pictures of plants on the ZIP-lock re-closable bag. Same product, 30-50 times more expensive.
