With a 2-year contract agreement, Costco offers its members preorders of the Apple iPhone 6s 16GB 4G Smartphone for T-Mobile in four colors (Rose Gold pictured), bundled with a $25 Costco Gift Card and Accessory Bonus Pack, for $649.99. This $100 mail-in rebate cuts that to $549.99, which can be paid in monthly installments of $27.08. With free shipping, that's $100 off list and the first discount we've seen on the iPhone 6s. Deal ends September 24. The phone is scheduled for release on September 25.

This new model's features include an A9 chipset, 4.7" 1334x750 Retina HD display with Ion-X glass (the same as the Apple Watch Sport models), 2GB RAM, 16GB flash storage, 802.11ac wireless, Bluetooth 4.0, 12-megapixel iSight camera with 4K video recording, 5-megapixel FaceTime HD camera with Retina Flashadditional multi-touch features (including 3D Touch), Taptic Engine (for haptic feedback), and 2nd-generation Touch ID.

A $15 activation fee applies.