I think in this case, everyone is right. Because it boils down to just that: opinion. I think in any market connected to a "hobby" you deal with this. There will always be artificial market inflation thanks to scumbags looking to cash in or flip. It frustrates everyone, including the people that only collect. But especially hurts those of us that want to play these games.
True, we could play teh roms all day. But for many of us [speaking of myself especially] I am acquiring games I wanted when I was in high school but couldn't afford. [see: Die Hard Gamefan ads with tons of import screenshots] I am buying the real thing to play because I get an emotional connection from touching and experiencing "the real thing". I realize its purely a nostalgic connection, but it is what it is and I don't get that from roms.
Something like these bootlegs manages to do a couple of things:
1. tickles my fancy of getting to play physical copies of these games that I can't afford or won't buy [in this case Sylphia being the only one I can't justify dropping $300+ on]
2. buying something brand new that's PC Engine related. Be it official or not. It's fun. I get a colorful new package in the mail to unwrap and look at.
Unfortunately there is nothing we can do about morons who pay inflated prices because they are impatient or ignorant. It has zero to do with value/gameplay in these instances. In my opinion it is just an unfortunate side effect of living in the time we are in with internet, ebay, etc. Its only going to get worse.