There is a link in the comments to a 7 dollar phone that looks way more polished. Crazy really, a fast food meal will cost you more than that here in Canada.
I think one of the ways in which they were able to undercut MTK was to use a different CPU core - the $2 MT6250 in bunnie's phone still uses an ARM core, which means licensing fees to ARM are some part of the cost (I'm not aware of any "pirated" ARM cores) - and in such a cheap SoC, could be a significant fraction. The RDA8851 is "MIPS-compatible" so they aren't paying ARM and likely the other IP on it was either designed by RDA or others in China.
It's no iPhone, but I also get 8-10 days on a charge:
http://www.tigerdirect.com/applications/SearchTools/item-det...