TL;DR: MTG card value is driven by three primary factors: mechanical utility in competitive play, historical scarcity (the Reserved List), and modern artificial rarity (serialized cards)
Card Set(s) -EMPERORS IN THE NEW WORLD- [OP-09] CARD VIEW OP09-106 | C | CHARACTER Nico Olvia Attribute Wisdom Block icon 3 Effect [On Play] Up to 1 of your [Nico Robin] Leader gains +3000 power during this turn
Number 158 Language English Not Legal Formats Alchemy, Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pauper, Pioneer, Standard, Timeless, Vintage Rulings (1/19/2018) If you draw a card, you can draw from any of your four libraries
2 Deoxys ex: POP Series 4 (Ultra Rare) $168.26 Striking Speed Forme Art Sceptile and Deoxys set quite a different tone than Mew's adorable scene, with this mythical Pokemon's depiction striking fear into your heart like a bolt of lightning
You can't choose to pay any alternative or additional costs for the copy
Its a great way to see what they value and catch any "bad trades" before they become a massive issue