How about a multiple of the amount with a cap on it. For example pirate one $40 book and it is $300, pirate $100 or greater it is $1,000.
Community service would be a big deterrent for most fundamentally honest people, as they would be inconvenienced and we know how much we hate that
plus maybe having to explain why or excuse it away. ANd not something easily forgotten, plus it might do some good for the community.
Helen