They are not selling accounts, they are doing leves for the gil. 10k/leve, x 20 rmt x 99 leves x 8 accounts = a massive amount of gil. They have a level 50 in the group go kill all the mobs, the tarus just turn leves on and collect gil.
But nothing will happen, because SE sees this:
http://xivpads.com/-up/i/RMTs.jpg
