For paid Prime members only, Amazon offers preorders of the 4th-generation Unlocked Motorola Moto E Plus 16GB 4G LTE Android Smartphone with Lockscreen Offers and Ads in Gray for $139.99 with free shipping. That's $71 under the lowest price we could find for the standard version without ads elsewhere. It features a Qualcomm Snapdragon 427 1.4GHz quad-core processor, 5.5" 1280x720 water-repellent touchscreen LCD, 2GB RAM, 16GB storage, 13-megapixel rear camera, 5-megapixel front-facing camera, 802.11n wireless, Bluetooth 4.1, microSD card slot, fingerprint sensor, 5,000mAh battery, and Android 7.1 OS (Nougat). The included offers and ads will appear on the phone's lockscreen and feature personalized deals and recommendations.

Also for paid Prime members only, the 32GB version in Gray is available for $159.99 with free shipping. That's $73 less than you'd pay for the standard version without ads elsewhere. These phones are set for release on August 11.

Note: Free-trial Prime members are not eligible for the prices above. However, free-trial customers who purchase the 16GB phone during the promotion for $179.99 (or the 32GB phone for $199.99) can receive a $40 Amazon gift card if they become paid Prime members when their trial period ends.