Boost Mobile offers the iPhone XR 64GB 4G Smartphone for Boost in several colors (Black pictured) for $649.99 with free shipping. That's tied with our mention from two weeks ago and the best price we could find for this on another network by $99. This recently-released iPhone features: it features:

A12 Bionic chip (shared with the higher-end iPhone XS)

6.1" Liquid Retina 1792x828 LCD display

Advanced Face ID

single-lens, 12MP rear camera with depth control and Smart HDR

7MP front camera with Animoji and Memoji

dual SIM card slots

iOS 12

Note: The 128GB option is available for $699.99 and the 256GB for $799.99, both with free shipping. They're both $99 less than what you'd pay elsewhere for them unlocked/with another network.