Apple Store Retail price: $588.
Used price: $250
Adapter only: $180 (w/o cable)
I got it from Suning, the official Apple dealer.
Working properly. I got 2 power adapters, bought an extra for home. Sold one with the console, therefore one spare left.
Please see attachments for photos.
Trade along the Tung Chung Line from Tsing Yi to HK only, or IFC Mall.
Thank you!