it should be around. i have seen a WTS post on www.hkpro.com
also in 9mm it's on gunbroker.com
Had one in the 70's and have never seen another (.45 DAO)
The P9S has not been made since the early 1980s, but they are still around for sale. It is one of my favorite pistols. Never seen one in DAO.
+1 to the above posters. You can still find one for sale here and there. Watch HKPro. I see them there more places than others.
Got one in 9mm and really enjoy it. Great trigger. A BUNCH were available a short time ago and police trade-ins. They were available from AIM, SOG and a few other of the surplus distributors. Always a few listed on the online sites (Gun Broker, Auction Arms, Guns America) It's finding extra mags that'll be the hard part.