Is This Set Rare?

Is this little set rare or unique that it would demand 10,000 yen? What does it do or what makes it so special?

Since the pictures have disappeared from this thread, I'll put these two alpha system sets released 13-Nov-2003 here:



The description for this one is roughly translated as "Hokuriku limited express Thunderbird has appeared as a Sound Plarail! You can enjoy starting and stopping with the card, and sound that matches the station and other scenes when the vehicle passes."


I'm guessing this is the set being discussed above: "Scene parts for 'Sound / Limited Thunderbird Set'. When the Thunderbird passes through the tunnel, a passing sound will be generated, and the signal will be randomly generated such as voice or Thunderbird stop / departure. Includes 2 plastic kids"