Like most Pokmon cards, the value of Wailmer depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Journey Together)
Thats the default, but some blink effects specify whose control the creature returns under
Blaziken's card in this set might be a stretch as a top chase card, but you could easily bill this card as a top-tier option in most other sets
Throw in a handful of dual lands and some playable utility lands like Bojuka Bog and Geier Reach Sanitarium, and counting only rare lands and other lands worth over $1, and the average value of the land slot in Commander 2019 has roughly doubled since last year, with the Sultai Morph deck clearly leading the way thanks to the Battle for Zendikar dual lands and the Jeskai Flashback deck lagging behind with a surprisingly lackluster mana base (especially considering it's a three-color deck)
Then, the pack remains on the Wonder Pick menu for awhile, just to torture you