Quote Originally Posted by Loony BoB
I'm not sure if having the ColCat will take away a bit of the odds of getting a rare item by making it more likely to get a regular item. Someone else might be able to advise on that?
The way I've heard it told, the odds for receiving a rare item are calculated first, and getting a rare drop excludes getting a normal item. So if you were farming Adamantoises for money (platinum ingots -- normal drop), you would not want to have a Connoisseur Catalog equipped (slightly increased chance at rare drop = slightly decreased chance at normal drop). However, having Collector's Catalog equipped should not have any impact on getting the rare drops, considering the normal drop odds are calculated last.