Haunted Catsacks cost 5 Ghoul Coins (~30 minutes of playtime) and are a rare drop from Halloween Remains, so I feel like it’s not unreasonable to assume they’d only contain items that aren’t in stores or are in the Ghoulcery Store, but I’ve gotten Dungeon Cell Bars (sold at DIY for 600 Units) and Dungeon Shackles (sold at Celebrations for 300 Units) from them.
I know the whole thing with Catsacks is that you don’t know what you’re gonna get, but with how obnoxiously long it takes to get enough Ghoul Coins to buy anything meaningful it just feels really odd that you can spend them for these and then essentially end up wasting them by getting something that you could buy several of by playing any of the minigames one time.