Barrel sets show up once in a while but when you're actually looking for something specific they are very elusive. Some people look for years and never finf what they need. Thirty-inch twenty gauge barrels? . . . take up another hobby
No, not $1K . . . I think I paid Russ $600 per set but I'm not certain - best to contact Russ about his rates. Whatever it cost, it was worth it - his work is absolutely first class.
And Yes, you can have Damascus barrels fitted. Russ fitted a set of Damascus barrels to my DH that was made with Titanic Steel barrels and they work perfectly - great chokes too! The Titanic barrels are choked full/full and the Damascus barrels are constricted .005"/rt and .018" left.