I've contacted @Flengo about this, I also have reason to believe this is a ban evader known as Safe Keys.
If you look at the posts no one else is posting on any other thread with multiple accounts saying "I added you on skype can I buy 3 keys". I don't really care if your using a vpn to fly under the radar its clear as day what you are doing. The DayZ trading section doesn't even get that much traffic so its ridiculous that you are trying to get away with this.
It's as simple as the user has a MPGH bot that uses proxies to create accounts and post on his thread. I know so because this program originated on his website.