It does seem like a good idea. Make a cash shop item for like 9000nx that enables you to move your character from one server to another, changing the name in the process if someone on the other server is already using it.
While it would mess with the in-game economy slightly because people could bring items from the really cheap servers to the really expensive ones eventually this would balance out, and in fact it may be beneficial because it would help even out the prices on all of the servers. Biggest concern would be if they didn't set enough restrictions on the process people would exploit it by perpetually moving their characters to whichever servers have the highest and lowest prices overloading them.
