I got it from a chemical shop its just zinc stearate i got like 500gm for 30 cent, but i do not use it. it makes fans really good but other sleights are not too well with it.
I get mine from my local magic shop for like 3 bucks but I don't even bother any more. Sure it makes your fans feel great but as others have mentioned....your sleights will be terrible. You may want to put some on one deck that you like to do fans with just messing around.