When a bundle makes sense
A bundle earns more than a single item when enough fans buy it. Because it costs more, it needs a lower buy rate than the single item does to earn the same. If your fans buy single items readily, a bundle at a modest discount is a low-risk test.
Keep the discount honest
Describe everything in the bundle and compare it with the real single prices. Discounting too often teaches fans to wait for the next deal, so keep bundles occasional.