What I did was have my retainer for the new character bazaar something then had the old character with gil buy it.
The reason I started a second character though was to play with a friend in a different city. The one with the items I want is in Gridania, the other in Uldah. The market zones within each city aren't universal are they?
You're probably better off just taking your first character to the city your friend is in. Depending on where you are it can be a lengthy run but as long as you stick to the roads there's nothing that's going to try and eat you along the way. You can summon your retainer from any bell in any city, regardless of where it says they are. As far a I know, you can't move your retainer to another city.