Hey I saw this in a magazine here, Swedish Level nr 87 like Oct issue 2013.
They have an article going to Super Potato in Akihabara, and they actually got to take it out and took a photo, it's the exact same ones as Tatsujin saw.
The article says:
Kid's Station - Complete Collection
Price : Unknown
- This is the complete collection of the edutainment-series Kid's Station for PC-Engine Super CD-ROM2, the games never got released in usual stores, it was only for students who used the Kumon study method that could buy the games in the beginning of the 90's, Therefore the games also became unusually rare. They have gotten a bid on 130.000kr (20.000$) - and refused.
End Of Article.
The games are complete but as you all might say might be missing a specialized controller, no mention of that..