What are the rarest/most expensive English booster boxes and booster packs?

[pokebuffet]

[Posted in another thread.]

[bk2021]

Which set will run out first?

Surely it’ll be one of the sets from Gen 3/4/5?

[trainerjack]

In terms of the games department, Emerald is the lowest selling Pokémon game, so that definitely corroborates 2005 being the lowest mainstream point for the franchise.

[Charizard1020]

I’m curious to see where a guaranteed shadowless booster box would fall in this?