Would definately offer opportunities for expansion not thought of. Instead of Teir 1, 2, 3... you get to choose what the space looks like *perhaps tht space having a specific level based on how many item slots it has) an), vanity items, or Big Ticket items like group buffs that hit whenever x number of guildies are in the same instance.

The one thing I'm concerned about is it'll all be toys that you literally could not get without platinum. Maybe make the guild halls buyable, but have the actual Stuff something you can buy for an obscene amount of credit, or a moderate amount of platinum (since stuff like discount craft stations and ESPECIALLY group buff items would be game changers... they need to be accessible by everyone.)