I have a near-mint copy of Rakugaki Showtime (with case and instructions, no spine card). I know this is one of the rarest PS1 games out there.

There's currently a mint copy for sale on EBay, with the guy asking $400.

About how much would my copy be worth, and how much would it be worth with the spine card? I'm curious how much value those little scraps of cardboard carry.