Currently on offer at Amazon UK for £42.50 for three: https://www.amazon.co.uk/dp/B086TMF7VG
Hardware specs are listed on techinfodepot, highlights being a mt7628an chipset, 8mb flash, 64mb ram, both 2.4 and 5ghz WiFi.
There's also a teardown with pictures of the motherboard:
http://en.techinfodepot.shoutwiki.com/wiki/Mercusys_Halo_S12
Would anyone be interested in seeing if it's possible to get openwrt working on these?
Ethernet ports are limited to 100mb fast ethernet.
Mine are arriving tomorrow