GiftCardMall via eBay is selling $100 eBay gift cards for $95. Unfortunately they have imposed a limit of 1 card per eBay user.
These gift cards are popular since they can be used to purchase other gift cards or merchandise on eBay at a discount. For that reason deals like this tend to sell out fairly quickly.
Update: SVMGiftCards is also selling $100 ExxonMobil gift cards for $90 with a limit of 3. (I don’t have any data points as to whether gift cards purchased from SVMGiftCards earn 5X rewards with the Chase Ink.)