$$$ WANTED - Vectrex "MineStorm II" cartridge - $500 Bounty offered $$$

[3DOMan]

Details are slim about this rare item, but my sources indicate the last one on ebay went for this price so I'll use it as a starting point for an offer. It MUST be an authentic original, not a repro or a fake some guy made in his basement. I'm getting very close to having a complete Vectrex set, so any help in finding this game would be greatly appreciated. Thanks