As Corbin mentioned in his post on June 4th, the dealers had to compete with buylist prices for chase cards like Tarmogoyf because even though only one or two vendors had a high buylist price for the card initially (the $130 and higher range) that meant that everyone else eventually had to raise their buylist prices in order to snag some Tarmogoyfs for themselves
Since Secret Arcade turns every permanent you control into an enchantment, playing Ondu Spiritdancer allows it to create an infinite chain of self-copies
when this is combined with the cards rarity as well as the fact that the card depicts a Shiny Pokmon, it can be seen how together, these factors elevate the cards overall value
Finally, you can just use it to draw two cards and lose 2 life, like Sign in Blood and similar friends
So, why isnt it placed higher
Collector Booster offer onlyfor purchases in the physical store