When T-Mobile first announced that it would be bringing the world’s cheapest Windows Phone device, the Nokia Lumia 521 to users for just $149, many people might have thought that deal couldn’t get any better. With AT&T and MetroPCS’ announcement that they’ll both carry a version of the device on their networks, it just did.

MetroPCS will make the Lumia 521 available to users in select markets, starting today for just $99. As T-Mobile and MetroPCS just finalized a deal to merge with each other, it’s likely that the availability is limited to the markets that T-Mobile and MetroPCS have already merged operations.

AT&T GoPhone users will be able to pick up the Nokia Lumia 520 for $99. Though its name is slightly different from the T-Mobile and MetroPCS variant, rest assured it’s nearly identical to the Lumia 521 in every meaningful way. In addition to coming with a full slate of AT&T applications like, AT&T Radio, this device will only come in black.

The Lumia 521 and Lumia 520 has a 4″ inch display, a 1 GHZ dual-core processor and 512MB of RAM. Although users do have a 5 Megapixel camera on the rear of the device, there is no flash, so users will have to make do with taking photos in situations that will sometimes be less than ideal.

Each version of the device also comes with 8GB of on-board storage, however users can add more storage using the built-in microSD card slot on the side of the device.

As the Lumia 521 & Lumia 520┬áis a prepaid smart phone, users looking to replace a battered older Windows Phone, or a Zune HD that simply isn’t cutting it anymore, should find the device pretty compelling.