Polly I bought it from more a commercial turf supplier here locally it was 135.00 for a 50lb bag but one bag lasts me 2 years with great results if your interested I would maybe look at like a farm supply or figure out where your major lawn care companies are buying there products I think it is fairly popular product amongst Farmers or growers.
Paul that seedling bed looks great its amazing how fast they grow when they are happy.