Crown Zenith's nearly $100 Booster Bundle blows most others out of the water, and you can expect these prices to become normalized for sets that go out of print
When a Pokmon is under the Poison status condition, it takes 10 damage at the end of every turn for each Poison counter on the card, which can be enough damage to knock out a significant number of low HP Pokmon
That means if you want an ex card, you will have to trade another ex card in return
It also has plenty of removal spells in Casualties of War, Putrefy, and Tear Asunder, if a particularly pesky Voltron player is threatening to block one of your many, many little critters
6 damage-counter dice
I dont find deck building particularly engaging, but something about the moment-to-moment turn-based tactics did it for me