Looks like a version of this:
http://www.aliexpress.com/item/AIEK-M7-mini-card-mobile-phone-children-gift-mini-music-phone-6-5mm-Ultra-Thin-mini/32282802441.htmlYou can find them for about $16 with free shipping from China. Moreover, that phone has a better display.
I guess the $100 on the Light Phone is mostly for the prepaid minutes, but even that is quite expensive.
There was also the "Gongkai" phone from Bunnie, I believe it is the same thing:
http://www.bunniestudios.com/blog/?page_id=3107The "Light Phone" looks very much like just rebadged version of it, bought for a few bucks in Shenzen somewhere and then re-sold with a prepaid SIM card to suckers on Kickstarter.
If you look carefully at the images of the "3D casing" prototypes, the PCB in one looks very much like having the cheap OLED display module that the Bunnie's phone and the Aliexpress phones have, not that simple LCD they advertise. The board looks very similar too, with some minor differences - probably depending on what the factory got in stock this week ..
I would be also very careful about the "works everywhere" claims, because for roaming to work (for the phone to be able to sign into a foreign network), the operator that issued the SIM card needs to have contracts signed with the network where the phone is going to. E.g. here in Europe it is very common that I am able to use only one, at best two networks in every country through which I am traveling. If the "right" network isn't in range, tough luck, no calls except emergencies. So the backers could end up a with an expensive but ultimately useless sim card ... EDIT - scratch that, they don't ship prepaid minutes nor SIM cards internationally, so that is a moot point ... So you get just that $10 phone in a custom case and a t-shirt for those $100 after waiting a year - what a deal!
Re usability and market for these things - I think there is a legitimate market for cheap, essentially disposable basic phones. Traveling abroad and your phone doesn't support local network? Don't want to give kids a $600 iPhone to break while playing outside? Basic backup phone when going hiking? Perhaps even your grandma would appreciate a simple phone like that. However, there is no need for that "Light Phone" rip-off, IMO.