They should make double items like those and just double the crafting cost. Might not be any more difficult than adding normal items? But it'd be nice if they would do something like that. Maybe even add the Star Ruby/Sapphire Music Boxes from the GSM quest to the list, and call it like the Star Jewel Music Box (unlocked by completing the quest you need to make them for), and bonus points if it can do both tunes at once.