The U.S. shooters asked, why a 9mm revolver when we have .38 specials and .357 magnums in the same frame size? So, S.W. never ended up making a lot of these guns (maybe 10,000 or so). Certainly not rare but not real common either.
Was this before it became cheaper to shoot 9mm than 38 Special? Because now we know why. When you can find it, 9mm is cheaper than anything I've seen except 22LR.