Those look gorgeous grasshopper. Ignore that statement if you are younger than 40, lol.
You're brother is going to be sorely disappointed in his wager. I know nothing about the strain you are growing but from the looks of those plants you are going to be harvesting well in excess of 1oz per plant. Mine generally get around 100 grams dry. Looking at the health of those, you are killing it so double down on that bet!