Steam notifies you every time a wishlisted game goes on sale, even 5% off.
WishSnipe connects to your Steam account, imports your wishlist, and checks prices every 6 hours against historical low data. It only alerts you when a game hits its historical low or your custom price target.
Each game shows a deal quality badge (Historical Low, Near Low, Good Deal, Wait) so you know at a glance whether to buy now or wait. Free to use, just sign in with Steam, no password stored.