That page you linked to is accurate for those items they are describing. Each area of collecting has its own set of guidelines pretty much. MIB stuff has a different set of standards compared to MOC stuff. Take puzzles and board games. Both of those would have 2 different C scales to each other. The puzzles would be for the box and puzzle. Games, box, board and game pieces. Get what Im saying?
But all in all, one persons C9 is anothers C7. If you didnt already, ask the seller for pix of every angle of the box so you can judge by yourself. If your still not sure, post the pix up here and we can help you alot better. Without the pix, its very hard to give you a straight answer to what you need to know.