The land base is another easy way to reduce the cost of Commander decks right now, as so many lands have steadily risen in price over the last few years that if you want to run mostly non-basics, it's going to take up a huge portion of your budget.
Very few versions, even Secret Lair versions, are worth more than $3
A Pokmon card is valuable based on several factors, including its age, eligibility, what set it was released in, the physical quality or condition of the card, the rarity and desirability, and the Pokmon/character/item that is featured on the card
cards like Battle Screech, Lingering Souls, and Secure the Wastes generate enough tokens for an activation and then some
It's a unique effect and provides a ritual of mana in Treasures if folks are able to take it down