Even today the more high-end Invocations, like The Scarab God, still command value over $200
It's not an "instant win" emblem like some planeswalkers have, but it's definitely going to get a ton of value from getting tons of tokens for free when other players just play Magic the Gathering as normal
The impending mechanic means it can provide land acceleration and mana fixing as early as turn three, and it can continue to provide value when it attacks after becoming a creature four turns later
However, Lucky Dime helps here, as you can use it the moment Belle is played to gain an instant five lore
Those are green-blue, green-black, and green-red
Id be looking to buy Blood Moons around $20 and Goblin Guides at $12-$15