For anyone interested, the $30 smartphone seems to be from a special Christmas time deal from CherryMobile [1] (a Filipino phone retailer) and may only have been valid at brick and mortar stores. It'd be much more reasonable to compare something available online with worldwide shipping even if it is out of active production. A Geeksphone Keon is comparable in price to an Arduino with equivalent shields and a heck of a lot easier to work with if you're not a hardware person.
The 30$ phones are based on the Spreadtrum SC6821 chipset and are sold around Asia. There are four different ones in India alone (Intex Cloud Fx f.e.) that go for this price.
Probably can get some SC6820 phones as well and make a port. Don't know if those are readily available in western countries.
Its though to get your hands on the super cheap handsets in US / Europe. But if there's sufficient interest we can go to an odm and just order 20,000 for <25$.
Edit: the cherry mobile phone went for 23$(!!) During their intro offering
I went to the trouble of getting an Intex phone. Even for its price it's not worth it - even if I can build the JanOS/FFOS sources I don't think I have the driver to flash the phone.
[1] https://www.facebook.com/cherrymobile/photos/a.299251607442....