Why isn't the unturned stockpile outfit "Spartan Armor" and "Valiant Knight Armor" tradeable?

[Sh4dy]

As you can see from browsing my discussion history, I have asked many questions concerning the spartan and knight armor skin for unturned, It has been 7 days and when I did some research on it, it said this ""Valiant Knight Armor" can only be purchased for your own account at this time." That mean's that I have wasted 5 dollars.... So I asked this just to make sure to see if there was another way of trading it and, if you could send money to your friend.