[timprov]

Ohhh K. He's ahead, you can only catch up with your 8 outs, you win 3 BB when you make the draw and lose 1 when you miss, plus there are 5BB in the pot.

You've seen 7 cards, so there are 45 left in the deck. You'll make your draw 8/45 times on the turn and 37/45 * 8/44 times on the river. To estimate, call that .178 + .149 or 32.7 % of the time. So out of 1000 tries you'll win 8 BB 327 times and lose 1 BB 673 times, for a total of 1943 or 1.943 BB per trial.

So you win $1943.

This is pretty simple, and everybody ought to understand it.