Looks like a heck of a buy to me. Not long ago, I sold a 16ga NID to one of the "chain" gun stores for $850. 12's will certainly go for less than 16's, but that one went at a bargain price in my book.

The reason you don't see a lot of NID's around is pretty simple: there weren't that many, comparatively speaking. Only about 45,000 total, more than Parker Trojans, but far fewer than Fox Sterlingworths (over 150,000 of those).