Is it against the ToC to sell carries?

[Yshnal]

I can't control where these people get their gil from ><

That's why the decision to take the risk or not is yours. You wouldn't have any reason to come back complaining if SE ever deletes the gil that you got from any of your customers, tho.

But that's one of the resons why I'm against selling runs. It makes it more likely that some weak-minded people consider buying gil from RMTs, with all the consequences for the rest of us.