Just a thought on this thread....any hay a horse can eat, so can a rabbit. Find the equine community. I buy lots of hay from a grower that grows and bales his own hay for his show horses that are worth tens of thousands of dollars each. I have no worries about the quality of hay. I routinely buy hay from him at less than $5 per bale. And his quality rivals the "brand name" hays at many times the cost. And if someone feeds it to his horse, you can be assured that it is good hay. A horse and rabbit gut are almost identical and both are very sensitive to mold.
And you do want a mix of hays. I have no idea where the thing saying "timothy" is the only or the best. Hay does several things. First, lots of hay keeps the GI tract in good working order. High fiber keeps things flowing thru nicely. Second, hay is the primary way to keep those teeth worn down. Contrary to popular belief, it's not how hard something is, it's how chewy it is. Wood blocks and pumice stones are cute and they are profitable for the pet stores....but they really don't do anything for the teeth. It's the tooth to tooth contact that wears the teeth down....and also why proper occulcion is necessary. Hay is very chewy and takes a lot of effort to chew....keeps the bunny busy too. If you watch, they don't really chew up and down in a crushing motion.....it's a side to side motion in which they are actually folding the hay stems into something that looks like an accordian. By using different types and textures of hays, it requires different chewing mechanics and works the teeth in a different motion for each type of hay. There is a difference in first and second cut timothy hay. Orchard grass, bermuda, brome, etc all have different textures and work the teeth differently. And stemmy hay is much better than leafy hay. And honestly.....wouldn't you get tired of eating the same old bland stuff your entire life? It's sorta like the rice only diet....and variety (safely) is the spice of life.
And the thing about alfalfa, it is true that alfalfa should be offered only as a treat to most adult house rabbits...but the bottom line in this thought.....alfalfa hay is better than no hay at all.
My buns have all sorts of different hays available to them. We even mix the hays to allow them to "forage" as they would in nature. They have a ball with a big pile of hay....I have "tumbleweed" bunnies.
Randy