PAL/R4 PS1/2/3 & PSP collector here; there’s no hard & fast cut-off rule.
But I would need to have a deep and personal connection to the title, and it would need to meet a number of requirements (case type, game variant, CIB, disc scratches etc.).
Even then, I’m still going to struggle to part with >$1,000 dollarydoos for Castlevania: Symphony of the Night Special Edition!