I'm curious about this myself. The company that makes it is a hidden brand of Hartz, which is HORRIBLE when it comes to most things, so I really don't trust them. They're likely to be unhealthy and expensive, although if the ingredients on the bag prove that it is just compressed hay and nothing else, then it's probably just expensive.
Can you take a look at the contents and let us know? (Even take a close up pic of the ingredients list?)
Meanwhile if you're going to a feed store, isn't there a way of getting hay by the bale or flake without having to buy the small commercial bagged stuff? Rabbits really need a LOT of hay and most of the time the bags are really not the way to go if you can scare up an alternative. The amount is small, the price is big and the quality is so-so. At least my bunnies tell me hay tastes much better straight from the bale.
Even if you have transportation and storage issues, its cheaper to buy a bale and just take what you can carry in a garbage bag.
Even if you can't find somebody selling bales close enough to you, maybe look for a farm with a horse, an equestrian center or even a zoo and offer them a few dollars to take part of a bale. It doesn't have to be timothy, any grass hay will do. (Just not alfalfa, or at least 10% alfalfa or less).
You can always mix it with a pet store bag.
sas :bunnydance: