The only people in the game with too much money are high level characters. Bring back Gregory and have him sell T6 potions and scrolls made by the Archmage Darkstaff at high prices. Done right these would give the player a real edge in adventuring, which would give them the money they need to by more potions and scrolls. They can be farming for all the hard to get comps while they are out there.
The advantage of consumables is... they are consumed. Letting people have custom banners would be a one-time deal instead of a real money sink.