Hi, i send you some answers via ebay.
Yes, there is a plastic-slim case, which is known for such Maxi-CDs with the special Promo-Cover. Looks genuine to me, anyway. That disc is silver-coloured and not golden, like the other 5-inch CD-V-Discs.
I think it is genuine and manufactured in Germany, in Hannover-Langenhagen, the first CD-pressing plant in the world in Germany. All other CD-V-Discs had been made in UK through PRS-Phonogram-Record-Service in UK via PDO, also the variants with the NTSC-System for the US-machines.
Yes, the suggested price is a price between heaven and hell, as we in Germany say. A few years ago i have followed such a disc, and according to my knowledge it was a seller or a collector from France, who buys it for around 700 Euro, as i can recall.
For that money i will buy some cool Gold- or Platinum-Award-Discs by Dire Straits, immediately.