14 DAY TRIAL // The Lumia 640 is likely to be one of the many smartphones to receive the Windows 10 Mobile upgrade, so if you're on a hunt for a cheap Windows Phone handset, AT&T has a very good deal on this particular device.
The US-based carrier usually sells the Lumia 640 on GoPhone for $60 without having to commit to a long-term contract. However, if you want to get it really cheap, AT&T has a much better deal, which requires some spending from your part, though.
Although the AT&T Lumia 640 is available for just $20 at activation, you will have to purchase $45 or more airtime, WindowsCentral reports.
We reported last month that Lumia 640 was available for purchase at Best Buy for $30 outright, but AT&T has since beaten that offer by $10.
If you don't mind spending $45 on airtime and waiting at least six months to be able to unlock the smartphone, then the Lumia 640 is quite a good deal, especially that it will be upgraded to Windows 10 Mobile.
The specs
Regarding its specs, Microsoft's Lumia 640 is an entry-level smartphone that comes equipped with a 1.2GHz quad-core Qualcomm Snapdragon 400 processor, an Adreno 305 graphics processing unit and 1GB of RAM.
Also, the smartphone packs 8GB of internal memory that can be expanded up to 128GB via microSD card slot. The Lumia 640 sports a decent 5-inch IPS LCD capacitive touchscreen display that supports HD (720p) resolution and features Corning Gorilla Glass 3 coating.
There's also an 8-megapixel photo snapper on the back, which features autofocus, LED flash and full HD (1080p) video recording. The smartphone comes with a secondary 1-megapixel camera in the front.
The good news is AT&T supports 4G LTE connectivity and packs a decent enough 2,500 mAh battery that should provide up to 36 days of standby time or up to 26 hours of talk time.