Question: What links these 3 clues together?

Littlefoot
Ducky
Petrie

Last Question: Put these items in order from least to most expensive when they were released.

A. Sony Walkman (TPS-L2)
B. Commodore 64
C. Nintendo Game Boy
D. Speak & Spell

Answer:

D. Speak & Spell ($50)
C. Nintendo Game Boy ($89.95)
A. Sony Walkman ($200 Astonished face)
B. Commodore 64 ($595)