Fellwar StoneFellwar Stone is just a simple, cheap mana rock that may not always get you the colors you need, but usually does
On the other hand, there are cards that have been printed in very small quantities , and thats the reason players and collectors want to own them
The theme is instantly recognisable, which can make the table more accessible for players who do not follow every mainline Magic plane
Pantlaza's Discover ability means that each dinosaur you cast has the potential to trigger a cascade, letting you fetch up one or potentially more other random dinosaurs from your deck (worst case scenario you hit a mana rock or something)
For awhile, cards like Jace, Vryn's Prodigy were $100+ extreme outliers due to its power and prominence in that Standard format
There are many ways to go with it and there isnt really a right or obvious build