where did you buy that stuff? coz i'm not familiar with those price stickers
From Osaka's DenDen Town (I don't know the stores actual name). There are some great retro stores there. In fact after visiting Akihabara twice, I'd say DenDen is better for PC-Engine stuff.
This store's prices aren't the best, but they usually have some neat stuff. For example they've got one of those PC-Engine Artist printer things for sale. Theres also one of those golden Namcot Hucards (don't remember the game's title) however its card only. Plus on the second floor they have a shit load of MSX games, and really old stuff like an Atari Lynx, Vectrex, and a Famicom Box for sale. This is where I bought most of my rare stuff including a mint Sapphire.
Theres a few other good stores as well. One store has 2 copies of Sapphire in their case.
I actually live in Shiga-ken (about 1 hour from Osaka), so I usually go about once a month or so. If you ever want to meet up to go hunting, just drop me a PM.