Yep If I were you, I would go for Galaxy Core or any of the android phones. As long as you dont install too many apps, it should be fine. The reason I say Android is the Notification Center(there is no such thing in WP, there's toasts but very little information in a toast, and there is no setting to disable toasts for incoming SMSes,) , various widgets to include shortcuts right on your home screen, data/sync/wifi/bt toggle in notification center, whereas in Windows, you'll have to go to the settings each time(although this can alleviated by installing third party shortcut and keep it in your home screen. . Remember, on 620/720 or the 520, it's only 520MB ram so if you're in a mood for multitasking, be prepared to see "loading" screen more often than not. If you happen to use two apps and a browser at the same time, be prepared to see IE or UC browser on WP reload pages, as memory management on WP gives RAM priority to the currently loaded app, so all the pages will be lost from memory, and will need to be reloaded when you resume. This however doesnt happen with "Speed Mode" of UC browser. There's no other browser in windows phone. There's no direct dialer in Windows Phone, no individual call log, no way to see how long you have spoken to the person as well.. If your cousin is very comfortable with WP, then 520 is a decent deal, it comes with a battery that's slightly larger than the 620. 520 is easier to type, I feel 620 is a bit narrow when you use the keyboard in portrait orientation. 720 is a great phone for its price 15K last heard on snapdeal, a 2000mAH battery of its class, you dont see too many 4.3" phones with that kind of battery capacity. If camera is priority, would suggest 720 over everything else.
