I and BadgersOnTop are buying a lot of GunPowder. Paying 4r ea(252r/ stack)! log onto SMP8 or PM me or him here on the forums to sell! Buying in bulk!
I have a Double Chest of Gunpowder up for Auction on the Auction Forums, going cheap so far! I suggest you check it out. So far going cheaper then 252r a stack.