Correct me if I'm wrong, as it's been a while since I've played, but weren't Bastok, Windy, Sandy, Jeuno/Whitegate, Kazham/Norg AH's all separate. Yet people still sold stuff in each of the AH's as there was a reason to be in all the towns. As I see it here, as well as a lot of people it seems, is that there is no real reason to be anywhere else bu Ul'dah as that's where the main story quest takes you. Granted everyone ended up in Jeuno, which is why it had more stuff in it's AH compared to the rest, but did they ever truly need to be linked? Oh sure it would have been easier to find the cheapest Silent Oils/Prism Powders or Sole Sushi but would you truly have wanted it to be like that? If SE wants to fix the emptiness of Limsa and Grids Market Wards they need to give people a reason to be in these two towns besides spending Guild Marks and getting Guild Support. Linking them to one specific zone is not the answer.