The Penetration isn't going to be as useful as you'd think. Most Sniping happens with the Sniper shooting down on the target, meaning your shot is unlikely to hit anyone behind your kill. If your level to your enemy it'll be great, but then you have a much less optimal position to get clean shots.
I'd rather have the Bazaar Bargain for the consistent increase in charge speed. Faster Charge = Increased DPS.