I was in a local Army/Navy store last week and looked at switch blades. The cheapest was $50, the next up was $160 and the most expensive was $600. They were all well made knives and I coveted even the least of them. :-)
I don't know the laws for Montana. I suppose with CCW one could carry a switch knife, but I'm not certain.
This is really silly when criminals are using guns and a big kitchen knife is a better weapon.
You can get a CCW in MOntana for a knife, but I am not sure if that permits switchblades or gravity knives, either.