There should be some form of server transfer mechanism, but care needs to be given as to how it's done. It can be easy to upset the balance of a server, if toons are able to freely transfer as is. A strong clan on a strong server may not be the most dominate, but could be considered strong enough to dominate a weaker or younger server. If the whole clan transferred to the weaker server, I'm sure everyone on that server would be in uproar. Also economics of servers need to be considered. Abundant items on one server may be relatively rare on another and so be priced a lot higher. This could allow people from other servers to bring such items and completely change the economy of that server. I'm sure Nuada would be in uproar if end game players and clans had the ability to transfer across, bringing with them masses of end game boss drops and such like.
What seems like a simple request actually can be a bit of a minefield and could potentially cause lots of friction.
A couple dozen pieces of rare fashion isn't going to cause some shift in server economies. Now if you had an abundance of plat buyers move from one server to another, that would be different.