I've considered a pellet mill. It would be useful for combining fine ingredients that you would like in the rabbit's diet, any kind of powdered supplements, for example.
I had rabbits and chickens at the time, though, so it would have been doing double duty. Plus selling as much extra as I could mill.
The problem with going through the local feed mill is that they usually have a minimum of at least a ton, and I simply don't have enough animals to justify that. The small batch capability is valuable.