Want to buy a bass trombone, dual valve, dependant or independent, $800-$1100, willing to trade my Benge 190 or trade + cash, or buy outright.

Very rare to see a two valve name brand horn drop that low unless it needs serious work. I kept an eye out for one myself in that price range for about 6 months and the only things that popped up were Olds S23 and S24, which really weren't what we were looking for. In that range you are looking at getting one of the better Jin Bao's from Mack Brass or Wessex. You might have more luck in the $1500-$2000 range.