Staples has a sale on GAP gift cards with 20% off on a few denominations. The discount applies to $200, $100 and $50 egift cards. There’s a limit of 3 per specific item. There’s not really a resale opportunity here since such sales have been pretty common lately, but it could be a nice discount if you plan to shop at any GAP brands. You can get an extra 5x in UR if you use you Ink cards or Amex Simply Cash.
I don’t believe any portals will pay out on gift card purchases at Staples, but it doesn’t hurt to try.
Keep in mind that Staples DOES NOT sell more than $2000 of gift cards in any order due to Federal anti-money laundering regulations.