SVMGiftCards via eBay is selling $100 ExxonMobil gift cards for $90 with a limit of 3 per eBay user. This purchase will also earn 2% back in eBay Bucks and a couple of portals are paying 1.5% for eBay purchases.
While eBay merchant gift card purchases from GiftCardMall and Paypal Digital Gifts have been earning 5X Ultimate Rewards with Chase Ink cards, it is unclear whether purchases from this seller will earn 5X.
One way to possibly achieve a 5X return is to purchase eBay gift cards through Paypal Digital Gifts and then use those cards to purchase the ExxonMobil cards. If you go this route keep in mind that it takes a few hours for eBay gift cards to become active and there is a possibility that the ExxonMobil deal will no longer be available.