They aren't so rare everywhere. A gun shop in a town nearby here has quite a collection in their cases - all police trade-ins. They have at least one 915, a 39-2, several 6906's, a couple each of 5904's and 5906's.....and a few more that I can't remember. The most expensive of the lot are the 6906's, priced at $359.00. I don't know the internal condition of these pistols....most of them show a good deal of external wear, but several are quite nice.
Many of them have been there for many weeks.
VERY tempting.
There is a good chance that, as soon as the holiday is over (maybe this coming weekend) ....I might well take another trip to that shop.....and one of those S&W's just might come home with me.