DW 22's are common. The problem is finding them. They are not a high ticket item, so you don't see a lot in the internet sites. Hit your local phone book and call the gun stores/pawn shops. Either that or just visit them like I do.
You can also put some wanted to buy adds in the gun forums like here or the highroad.org. Either one you will get some comments.
Actually the last DW22 I bought, was because someone posted a picture on a forum and I commented it looked like a nice gun. Email came through quickly and I snapped it up. I don't remember the complete price, but it was right at 300$ for a 6" barrel, 8" barrel (Vent Heavy) box, tools, manual and spare sights. It was a very early Monson, that my team lead talked out of me to give to his 18 year old daughter. Great gun and she loves it. Exceptionally accurate!
Mine (the stainless 722 above) is darn accurate and getting better all the time. It is built on a 357 magnum frame. You cannot hurt the beast and it also has the same feel as a 357 magnum. It makes switching between the guns easy.
Good luck. Remember the best ones are from Norwich and Monson, try to avoid the Palmers, but every maker had some duds and great ones, just follow the trends.