PayPal Digital Gifts has a promotion on Southwest gift cards on eBay that can get you a decent discount. You will get 10% off if you purchase $100 or more. These purchases also qualify for 5X when using a Chase Ink Plus/Bold/Cash credit card through PayPal.
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This sale gives you a 10% discounts and it could easily be 15% if you use one of your Chase Ink cards through PayPal to purchase them. You can purchase up to 5 gift cards, and you will receive the 10% discount.