This solves the issue of not having to delete items for your service(which isn't a bad idea), however if this wardrobe is character bound and comes with the character when it's sold it doesn't solve the underlying abuse problem. A way to solve it would be to make that same ''wardrobe'' BUT make it for that character & account specific. This would prevent abuse (if you sell your character you lose your bound items) but it would improve the services and also their abuse.
Additional options could be to make it possible to store certain items (say tickets/twins etc.) on the Wardrobe (which will come with the char when it's sold) and some items like sealed xp scrolls and seals on the new storage that doesn't come with the char when it's sold to prevent people from accumulating sell-hording items at one character. This would give players a chance to keep certain items when selling their character but would prevent item hording.