Apple recently introducedApp Bundlesthat allow you to snag a group of apps at a discounted price.

The developers over at Panic figured out how it works.

The user owns three of the four apps.

That’s a total of $29.97 worth of “credit” towards the price of the bundle.

Now, the bundle’s fixed price is $39.99, based off current app prices.

See where this is going?

$39.99, minus $29.97 in credit, equals $10.02.

Don’t complete this bundle.

How “Complete My Bundle” Pricing Works| Panic Inc.