Guys im not really into the color hats, but i think greyhat is scamming.
Here is my trick.

There is a website, which is for rustkey sellers- -If im not allowed to paste links delete the thread.
Here is what you do:
Step 1: Post that you are selling rust key, ussually with price arround 15$-30$.
Step 2: Make attempt to scam the guy, like pay you and then you give him the code.
Step 3:You get 15$-30$.
Step 4: Party!