I think the only recreational 'products' that can compete with books for value are ones that enable access to an existing natural resource. e.g. a bus trip to the beach, hut fees in a national park, etc.
One I have used is a
12 month backcountry hut pass for $100, which makes tramping an amazingly cheap pastime if you avoid the main tourist areas.
(Still need to take books though, for the days when the weather doesn't co-operate.)