I've used aspen for years and recently switched to kiln dried pine in huge bags from the local mom n pop feed store.
10cubic feet for $8 and way better than the crap at petsmart/petco IMO
Buy local think global
I wish more people would think/act like this...
It's tough owning a store with everyone buying at the chains... That $3 at WalMart is probably only $3.25 at a local store, your neighbor who is trying to make a living.