That stain should be about $22. per gallon.  Check your paint stores.  I think the brand Sundance uses is SuperDeck.  If you want REAL quality stain try Sikken's.  You will only find Sikkens at a quality paint supply store (not Home Depot or such).  Speaking of: stay away from the Home Depot brands like Thompson's, or Behrs.  Find SuperDeck, Sikken's, TWP - Total Wood Protection, or something similar.  If your looking for the "grey" color it shouldn't be too difficult.  Oh, I'm a painting contractor by trade.