For anyone interested, the $30 smartphone seems to be from a special Christmas time deal from CherryMobile [1] (a Filipino phone retailer) and may only have been valid at brick and mortar stores. It'd be much more reasonable to compare something available online with worldwide shipping even if it is out of active production. A Geeksphone Keon is comparable in price to an Arduino with equivalent shields and a heck of a lot easier to work with if you're not a hardware person.

[1] https://www.facebook.com/cherrymobile/photos/a.299251607442....