its just a matter of ebay and many people not being aware of what is being sold, to them it is not obvious that something sold as a dietary supplement 3 months ago is now a schedule 3 controlled substance. most people dont know anything about it. average people have no clue that these are sterioids. if you were trying to sell cocaine or heroin on ebay there's a large risk that you will get in trouble because everyone knows what it is. ebay would probably report you to the cops! its not clear and obvious that x tren is illegal, unless you are in the know.
if i got busted selling it i would say that i bought this 4 months ago and it was completely legal and i was not willingly trying to distribute a controlled substance and did not intend to do so, etc. i was not aware that it has now been made illegal but i am now so i will quit selling it, blah blah and theres not much to worry about, if it went to the judge you probably wouldnt even serve time.