If you have a card from a raid, you should only be allowed to roll greed

[Kit-Kat]

Then how about once a card is traded from player to player once, it is unable to be resold or traded again.

Then it would make the problem this thread talks about even worse. People would still roll on cards just to sell them for gil instead of MGP. Also, TT is suposed to be a mini game for you to collect and earn your cards through effort. Cards have different 'stats' and actually affect the tournaments, so you could buy your way up there to get extra MGP from the reward. Same way as gear isn't tradeable.