That's a great price if you can get your local store to order it. If they can't, do you have a local seed and garden or farm and nursery mart. The seed and garden we have over here sells the 50# bags for about $39.99 and up depending on the brand. I believe Scott's slow release and the Florikan was the $39.99. Scott's is an excellent brand. Magic Carpet is another good extended release (I think it lasts up to 3 months?). It has an instant fertilzer that is released over a couple of weeks as well as the slow release. Red Fox is another brand like the Magic Carpet.
You may just need to call around because even if you look up who sells it on the fertilizer company websites it doesn't show every place that sells it because these smaller places get it from distributors or supply houses.