I'm helping a buddy of mine, sell his JB4 with the new G5 board.
Local pick up/Shipping
-JB4 G5 board
the G5 board has better control of several parameters (isolated boost control among other new features, and is a superior tuning solution to the old JB4 G4 board.
His asking price is 500$
Keep in mind the JB4 with the old G4 + USB cable is 509$. the upgrade I believe is 150$ to the G5. NLS/2STEP is another 30$.
Let me know if you are interested!