What if the adventurers find a full-color collating photocopier?
Consider: They open a cartography shop, able to recreate any map in mere moments. Since it's so easy, they take a copy of every map they reproduce, eventually compiling the most accurate atlas in the world, with every treasure clearly marked with an X.
Literacy rates will shoot upward since the bottom fell out of the book market, even though books are now bound with only a single staple in the upper left corner. Everybody earns training in history and geography, and many children learn the ways of the world with purloined copies of the bawdy (and graphic) "The Piercer and The Beholder".
When war comes to the kingdom, the party is put in charge of a generating and distributing propaganda leaflets which eventually end hostilities and lead to the annexation of the enemy country as a vassal state.
And don't get me started when they figure out the ink formula so they can photocopy viable magic scrolls. They'll have an unstoppable magic school where even apprentices can cast any first-level spell because scrolls are effectively free.
So it's not so much a party advantage as a world-changing device, but I still wouldn't want to be the gnome who has to keep it clean and free the paper jams all the time.