I got this, Miracle piano teaching system for NES sealed. I know the history on it, and know it was $500 in 1990 when it came out. But I've only found 2
Miracle Piano products for sale | eBay
Miracle Piano Teaching System, The - Nintendo NES Game Original Game CartridgeのeBay公認海外通販|セカイモン
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Miracle Piano Teaching System : NINTENDO ENTERTAINMENT SYSTEM: Amazon.com.au: Video Games
Miracle Piano (Nintendo, 1995) for sale online | eBay