Office Depot currently has an in store offering of $15 off Mastercard gift cards when spending $300 or more. I haven’t actually seen this offer myself but this is an excellent deal so I would check it out at your local Office Depot – this deal will end on 9/15/2018. Using your Chase Ink Cash will yield you a nice 5x multiple on points.
I typically liquidate mastercard gift cards by buying and selling gift cards via paypal. However I was able to use them without paypal on sites like Giftcardzen as well. But if you have your own method to liquidate these cards thats great too!