UPDATED to reflect AT&T's ongoing accessories discount, which can be found on this page:[att.com]
"Buy 3 Accessories, get 20% off. Available at select stores and at att.com. Pricing not valid with other discounts. Limit 10. Exclusions apply. Restocking fee: 10% on accessories over $200. Other restrictions apply. Subject to change without notice."
AT&T Wireless has BOGO offer: Buy one eligible iPhone and an iPhone XR on us when you buy both on AT&T Next Installment plan. Plus get $300 Gift Card when you order on line. See websites for additional terms and conditions. Shipping is free.