Making the items purchasable kinda takes a little away from the entire idea of it. I see the Casters/Fighters guild quests as sorta nostalgia quests. Sorta like heritage quests in EQ2.
I suppose putting a vendor inside the guilds with purchasable items would be helpful. Could make the items account specific so no giving to other people who didn't do the work. Then you would just need to get 1 char per account flagged. *shrug* Of course, considering most peoples alts are on different accounts this wouldn't help much.