I'd like to hop in and just say something.

Having markets linked is a good thing for players in all situations if you looks specifically at economics. However, if you looks at 'immersion' or 'realism' linking the markets may not be desireable.

In the absence of linked markets, usually people would act as merchants, buying products from one market transporting them to where the demand is. The problem is... you can't make much gil as a merchant when you're limited to 20 or so slots to sell. The point is... players acting as merchants would solve the separate market problem on its own ... if such an environment were to be encouraged.

This is essentially the ideal solution that satisfies all conditions. It allows players access to all supplies of eorzea wherever demand is created, and sacrifices no 'realism' or 'immersion.'

Why this is important is... the only real arguments against having linked markets are immersion and realism ( I understand that hardly anyone, even those interested in economic activity may find the amount of immersion and realism tepid at most), but the fact that there is no real sacrifice in either immersion or realism and the enhancement of the availablity of supply, which is the desired end in linking the market wards, is still achieved; I just can't see a better solution I guess.

If you open up many more slots for people to sell things, you could have an entire merchant class of players. This actually enhances the 'immersion/realism' and enhances the availability of supply.