Regarding card exclusivity, the most expensive version of the card can cost up to $17 per card
Collective Voyage + Minds Aglow I quite dislike the join forces mechanic in general, though I find Collective Voyage to be the real offender given how quickly it accelerates games out of control
Elesh Norn, Mother of Machines (colloquially known as Panharmommycon for its Panharmonicon-like effect) will not only give you another instance of Negans ETB effect but will shut down ETB benefits from your opponents
Add to this the ability to barter with customers who want to sell or trade, host playing tournaments in your shop, and set up events around certain cards and card types, and you have a living, breathing storefront
Liliana and Chandra acting like wacky siblings, complete with Liliana cutting off Chandra's necromancer jokes
The expansion includes new Radiant Pokemon, more Pokemon VSTAR, and the return of the Lost Zone meaning there are some seriously valuable additions coming your way