This would not only help the economy, it would help keep players spread out throughout the main nations.
Barely anyone uses the Main Nation AH's. And when they do, it's usually not for dire items. If all the AH's were connected, there would be less need for everyone to use the Teleport to Whitegate to use the Auction. Most people home-point in their main nation at this point, anyway. You can look at it as there are 5 AH's connecting to the one, but that's not really a reasonable argument. It doesn't really matter, because if you're home-pointed in Sandy, what's the fastest way to get to the Jeuno auction house? Use the NPC to Teleport to Whitegate. Aside from Airship to Jeuno, or running, you're going to go through Whitegate to get to Jeuno also. It's all a giant circle. In order to get to the useful auction house, you have to go to Whitegate, which bottlenecks the community in situations like what happened after the server merge.
Edited, Mar 24th 2010 1:17pm by Raiendel