Errrr...clearly you didn't.
what^^^
Apple manufactures these (almost assuredly in-house) and probably won't be too keen on letting them go (to put it in perspective, most of the mannequin you see in stores run ~$700-1K). You're just looking for the "Buy 2 pieces of plywood for $25.00, a mirror, and you'll be able to reflect it" answer, which doesn't exist. If you REALLY wanted one, you'd be making cash offers to the Apple store near you, calling Apple corporate, and be looking for a cheap 30" display....which you're not.
Yeah how do you know what i am doing???