The SMILE Plug contains the Marvell 88W8764 access point, with support for 60 Wi-Fi clients.
I believe that this higher-capacity, beamforming, enterprise-class AP is a major part of the price.
The device has two USB3 ports, a MicroSD port and two Ethernet ports, one DHCP and the other manual IP.
My understanding of the SMILE Plug is that it is intended for use in schools, institutional settings, public venues and the like.
It comes with Node.js based software from the SMILE Consortium. Those are highly specialized web apps for classroom use.
It is an Arch Linux ARM computer so different applications can be loaded on it. The developers have stated that a new OS image is being prepared that will not have the complex educational ware on it.
I agree that the price should come down. I believe the SMILE Plug has a lot of promise and have been experimenting with my unit. There is no question that better docs and more use cases are needed.