A:
When I contacted Bush about this, they said they can not sell additional shelves because these units are designed to function with the compliment of shelves they supply.
However, I am finding out that by purchasing an additional unit, that I gain 4 additional shelves just by using the horizontal pieces from the other kit. I have one right now with 4 shelves in it and it's perfectly stable.
This however is my decision and I can't condone another doing this.
Answered on 9/17/2010 by Joe the Trek man... from Glendale Az