The regulator was picked up already, I had a busted tank pressure valve but the unit still worked and the out let pressure was fine, it was free......
You can get them on ebay etc.
I think a number of vendors sell the milkwalk's for 70-80$.
Look around at Fire or Beer or Beverage places for tanks, refills etc, they are cheaper than welding places.
I get tanks for 20lbs for new painted steel tanks for 50-65$ ea filled.