I have seen megas saying Trading or Selling (NX) Gifts .
I don't really look for them though, but if by reading the ad you cannot tell that the person is only selling gifts, then that is a problem.
YOLO your first r7 scroll. Your runes will be used to protect the armor while putting the 2nd enchant on. I suggest starting with the chest/tunic since most people are good with master ES it makes it the easiest set piece to finish. If you want to keep making a progress I suggest trying to nail the first r7 on all 5 pieces first and then circling back around with runes saved over time.