Poetic Ingenuity, Otepec Huntmaster, Krosan Drover, Knight of the Stampede, and Knight of the Stampede provide faster means (including cost reduction) to dinos and important early support
As a direct point of comparison, this exact Marnie card appears in English's Sword & Shield Base Set, but only commands a fraction of her Japanese value, settling at around $30
Finks is low enough impact than a red deck can play around it or through it and still win even when it doesn't have the perfect answer
It is about fees, buyer intent, sell-through speed, trust, audience size, and how much work you want to do per sale
To calculate the mana value of a card with Phyrexian mana symbols in its cost, count each Phyrexian mana symbol as 1
Gravecrawler While I believe Bloodghast is a better recursive creature, I consider Gravecrawler a more universally powerful card, mostly due to its obscene combo potential