Grail
A desirable item
Example
A copy of Detective 27 is my grail comic book

Related Slang
HG | Holy grail |
Grails | A rare pair of sneakers |
Unicorn | Rare LuLaRoe item |
OOP | Out of production |
MIB | Mint in box |
NIB | New in box |
Dupe | A cheaper stand-in product |
Those searching for a rare or desirable item may call that item their grail. This slang term references the mythical Holy Grail which, in most tellings, is an ancient cup that provides its owner with eternal youth.
Any sort of sought-after item can be a grail. For example, a Pokémon fan might consider a first edition, holographic Charizard from the original TCG set to be their grail, while a foodie might consider a meal at Kochi to be their grail.
Some hobbyists use specific variants of grail to refer to their hobby's rarest or most desirable items. For example, those looking for a specific pair of sneakers may refer to those shoes as grails.