MJH have allot of buying power with Austral and sell stacks of Bowral Gertrudis Brown and Bowral Blue. I was VERY suprised to see our upgrade cost (had to ask for written confirmation that they had in fact gotten it right). On the flip side, other colours (like the Gertrudis Renovation) will require you to sell your left AND right kidney. Allot of it depends if it is a light, mid or dark colour brick (different shaped kilns for different periods of time).