It’s currently not possible to get a table of only collectible/limited items that have stock available. Resales are not supported in-game and items with no remaining stock aren’t always needed when populating an in-game catalog.
Please add a parameter that lets developers specify if the results for AvatarEditorService:SearchCatalog() should return items that have no remaining stock left, or if it should only return items that are buyable to the player.
Adding something like this will cut down the amount of calls a script has to make to populate an in-game catalog as it is not returning results that the player cannot buy in-game.
You can research ROBLOX endpoints a little to find the specific endpoint for searching the catalog and then combine HTTPService:GetAsync() along side with the proxy (roproxy.com) to get the data you need in game.