Pat the NES Punk talks about CIB Game Boy games
here. A quick except
"You know why it never took off? They're not out there. It's a weird thing where there was this want to go into it but it's almost like the lack of supply meant there wasn't enough embers to even spark the fire..."
Yeah, in terms of scarcity, some of these games make the "rarest" NES games look like Genesis sports titles they've been insanely hard to find. There's just enough of a Game Boy collector's market to spike maybe a dozen CIB titles into the $1000 zone, but not enough demand or notoriety to push somewhat less valuable games into the auction market. You'll pay four figures for a handful of NES games, but you can almost always find a few copies up for auction at any given time, because people know there's money in NES rarities; that's not the case with GB.
As an example, I've been watching for a CIB Boxxle II for more than a year with no luck... I managed to borrow a copy from someone finally, thankfully, but if it hadn't been for that I'd almost believe it didn't exist. A perfect storm of (1) a system with little collector prestige and (2) a format that encouraged portability (read: discarding boxes) has made the CIB hunt much more difficult than I'd ever expected. I'm making progress, though! I just paid for the next-to-last game I need for 1990 Vol. II; now I somehow have to get ahold of the box and manual for Fish Dude. Which is, yes, one of those games that has spiked into the $1000 zone, so I'm going to have to prevail on others' kindness for that one.