I got all three!!

They're so rare because they were only given away in a lottery in Japan in 2010 when the Zoroark movie was out.
I heard that only 150 of each pokedoll was made for the occasion. You had to spend a certain amount at the Pokemon Center store to enter the contest.
They were low odds, but if you got a blue marble you won one of the legendary beat pokedolls. If you got the red marble you won the complete set.
It's why the dolls are so expensive and rare X)

Only one of these guys cost me an arm and a leg tbh

Pokedolls Featured:
Shiny Entei Pokedoll
Shiny Suicune Pokedoll
Shiny Raikou Pokedoll