Want to stop gold sellers before it even really starts? Do as Tera does. Make an item purchasable in the crown store for $14.99 that adds one month of ESO plus once you use the item in game.
Other players can sell this in game for gold. Face it. People are going to buy gold and this will be a way for you guys to stop them from going to third party sites to buy it. It will add major revenue to the game for development.
This also solves the issue of people not wanting to put their credit card on the Xbox and people can now use xbox credit or trade in game gold to other players to buy eso+ subs. Problem solved and the devs over at Tera say it wast the best thing they ever added to the store.
I would agree.