For a low end phone the Nokia Lumia 510 is actually a really nice looking phone. Supposed to be lower than the 610, hence they named it 510. And Windows Phone 7.8 will be like a low version of WP8… there’s mass storage and BT transfer…but i wish memory card slot though…
But this has a bigger screen so I think that’s one advantage over the 610 and 710. I think the lumia 710 is a better option. it’s just $190 on amazon and has better specs.
Nokia Lumia 510 features include a 4-inch display, 5-megapixel camera, a VGA front facer, 800MHz processor, 256MB of RAM, 4GB of internal storage, five-megapixel main camera, and Windows Phone 7.5 operating system. The device will be priced below $205 and will be available to buy starting in November in India, China, South America, and Asia.
Source: The Verge