Sometimes it's simply impossible to get a group together for a content that nobody wants to do.. All you can sell at that point is either your good will or gil. It's not being paid to carry you, rather more of a convenience fee.

T5 doesn't need a carry, with the gear we have it's easy peasy, but people just don't want to do T5.. So, if I have to pay a million or two (which only ends up being like 200-300k per person) I think it's a decent trade off.

I've personally never bought any runs because I'm not antsy to get to the end-game raids, but some people are.. To some, that's all they want to do once they hit lv 50.