I recently bought a set of your 9mm to 40 dies second hand at an auction as part of a larger lot. Didn't need any of the rest of the lot, and I initially thought that I had been overzealous in my bidding. I just got around to casting some cores and annealing brass this weekend and just swaged my first bullets from those dies. I've got to say that it was worth every penny.
Up until now I've been making do with macgyvering commercial reloading dies to swage bullets and while that has worked fine, the ease of usage is night and day. With my macgyvered sets, there are any where from 4-6 stages, but with your dies, expand for the core and swage. If you made a .451 one-step die, I would be all over it.