I've got a couple Beretta Single Action handguns. I've got the Steel I you are asking about. I've also got a couple Billenniums.
The Steel I is an awesome handgun. I love it. Being all steel, it has a nice weight and great balance. It's a heavy gun - great for taking to the range, not so great for carrying around all day. As you probably saw in the picture in the Beretta catalog, it has the Vertec-style grip, as opposed to the standard, curved, 92-style grip.
The Steel I comes as either a DA/SA or a SA-only model. The SA-only model has the same configurable trigger-action as the Billennium.
It's a great gun and a lot of fun to shoot.
Not sure if they are still being produced by Beretta.
The last MSRP was, indeed, $1,600.00. And that is what they had been going for for quite some time. Recently, however, distributors have unleashed a bunch onto the market, and you should be able to get one in the $900 - $1,000 range (see this one here on GB:
http://www.gunbroker.com/Auction/ViewItem.asp?Item=68976101. I'm in no way affiliated with the seller, by the way).
If you are seriously interested in getting one, now is the time to do it, because once this current inventory is consumed, they'll be back up to that $1,500 - $1,600 range. In fact, if you do a search on Gunbroker, you'll find many in that range already.
If money is not a big concern, and if you have the patience to wait until one comes on the market, it's my opinion that the Beretta Steel I is secondary to the Billennium. The Steel I and Billennium both share many of the same components, but the Billennium has the standard grip (which I prefer), and is just a bit heavier than the Steel I. The slide on the Billennium is so smooth, it seems as if it runs on ball-bearings. And the weight and balance of the Billie is absolutely unmatched, in my opinion. It makes shooting 9mm feel as if you are shooting .22lr!
Good luck!