The most important factors are edition (1st Edition, Shadowless, Unlimited), condition (mint cards command premiums), rarity (holographic, secret rare, full art), age (vintage Base Set cards are highly sought after), and the Pokemon itself (Charizard, Pikachu, and fan favorites are worth more)
At the time of writing, the Starmie ex deck is one the best you can run in the TCG Pocket, with the Charizard ex deck not far behind it, so picking this pack starts you off well if you're planning on playing the actual card game
Lurantis ex #096 UR Loading
It seems like every time Wizards of the Coast prints a new lotus-like card, it presells for an exorbitant amount at first
This blue, black, and green creature has you discarding creature cards when it comes into play, mimicking the carelessness and ferocity the Dinosaur shows to other animals in the film