I get my cypress mulch at Petsmart too, I believe it's labelled "Jungle Earth" or something like that. It doesn't actually come out and say cypress unless you read the ingredients.

I've heard of people finding it at hardware/gardening stores too. Apparently you just need to be careful of any parasites hitching a ride and make sure there are no super large pieces. MUCH cheaper apparently. I'm going to be looking into it soon. The big $50 Petsmart bag only lasts me about a month with 13 snakes.