Apple isn't the first company to offer 4K purchases. Vudu has been selling UHD titles for years, and it typically tags them at $30 (though some newer films go for $25). If Apple wants to have a tactical advantage over Vudu, which is one of its biggest competitors at this point, it'll definitely want to undercut them somehow. Making things even more complicated, Vudu just recently launched an Apple TV app.

Just like Apple's earlier battles over music and film licensing, the company has to convince its more traditional partners that a lower price is better in the long run. And as someone who eagerly snaps up 4K Blu-rays, but refuses to spend $30 on 4K digital releases, Apple's reasoning makes more sense. Most consumers are used to watching video on inexpensive streaming services these days, so they'd probably completely ignore $30 titles.