Thanks Aaron, I should have added the link.
If you go to Lesco's home page and input your zip code, you will get the closest locations of their stores. You can then order it from the link Aaron provided. Lesco does not charge shipping from one store to another store in order to get the Soilmaster in stock but there may be a bit of a wait time. In our case (SWOAPE) it was about a week. A quick trip to the local Lesco and you will have 50lbs of substrate on hand for relatively cheap