Walk the gallery the way you would walk a real mall, step into a shop, get close to a piece, open its details and ask for the price. Every seller runs their own shop and puts their pieces on display themselves.
WASD or arrow keys to walk, mouse to look around.
Prototype: anything added here stays on this device (no database yet). What it changes in the mall, however, shows up instantly.
Here is every piece as a list, with the same information.