Another way to think about that...
$5 bundles, you could tolerate a 20% theft rate on a honor system box and still the net the same.
I'm sure there's a place for them, maybe a smaller campground that doesn't have a full-time store / ranger station, which also have modest theft rates, and where you can get a long term contract to allow you cover the cost of the machine.
Thinking back 20 years ago to when I worked a couple seasons for the Conn. State Parks in one of our smaller campgrounds (~55 sites between two nearby locations), probably half of those 20 weeks I think you'd be hard pressed to meet 50 bundles/week...but three weekends each season you'd be racing to keep them full each day.
Guess it comes down to knowing your specific market.