3G/4G modem

[acitta]

How can I buy a 3G/4G network/wifi router for $13, but if I want a cheap chinese arduino plug in module shield with the same parts it costs $100+?

If there really is a licence restriction on 3G chip sets then why can these be made so cheaply? 

http://www.ebay.com.au/itm/Mini-Portable-3G-4G-WiFi-Wlan-Hotspot-AP-Client-150Mbps-RJ45-USB-Wireless-Router-/172246907198?hash=item281ab7393e:g:990AAOSwc1FXZnc1

There are some tutorials on how to hack these for the arduino but they seem fairly tech heavy. Has anyone here done it? I've got one in the post that I'm going to play around with but I don't like my chances.