Jump on that...especially with both barrels! I paid the same price for my used one at a Scheels a few years ago, with only the rifle-sighted 18.5" barrel. (It was improperly tagged as a 22" rifled barrel)
The M1S90 is a Benelli, not a Beretta, and was imported by HK for a while.
Mine came with the standard stock, which I replaced with the Urbino listed above. It goes to work with me every day as a deputy sheriff. I'm 5'5" with 32" arms, and it works far better for me than the issued 870 Express that we are forbidden to "modify".