I am having good experiences with Kitty Litter. I don't recommend it to anyone since it is not made for aquariums, and each bag is supposed to be different, and might turn to mush in seconds and leach totally deadly things into the water... but it works for me. I had it for a couple of years in a tank that I just took down, and it still had the same texture.
I just set up a tank using KL
, just some peat underneath. Disadvantages -- it is light, like Profile, so planting isn't as easy as in Flourite. And the color is probably not everyones favorite, kinda cream/gray loamy, but some might find it natural looking, many planted tanks don't show any substrate anyway.
I am planning to redo my 100gal tank soon, and KL will be the substrate of choice, covered with some Flourite for easier planting and better looks.
Again, I am not recommending it, just wanted to mention it since it is a very low cost substrate, at $2.22 or so a 25# bag.