Eco Earth is just a brand name coco fiber actually. I personally have used 4+ brands. I find eco-earth is one of the best. I often have trouble finding it in stores though. I usually get exo-terra's plantation soil, since I can find at pet food express for 2.50 a brick. It's not quite as nice as eco earth imo, but my frogs don't seem to care either way
I've heard there are some really good deals online on Amazon and whatnot. The guy I bought my African Bullfrog from said he bought eco earth in bulk on Amazon at something like 1.90 a brick. Considering some retail stores will try to charge you 5-6$ a brick, that's pretty good savings.