Market prices change over time as copies are bought and sold
It seems like every modern Pokemon TCG release has at least one card that stands out from the rest, typically commanding over $100, and sometimes flirts with a $1000 price tag, like the chase cards in Ascended Heroes
As an additional note for this topic, Ravensburger has confirmed that the Enchanted rarity variants of cards will not be reprinted in any future set
Well, some decks have a Supporter infrastructure (Sableye SF) and can more easily grab a Supporter than a Trainer
Nyx Lotus has a slight value bump over Nyxs shrine when you consider artifact untap effects like Manifold Key
Jund suddenly had access to multiple efficient answers to any cheap threat, and you had to think long and hard if it was actually worth it to play any creature which costs three of four mana