Given the prices of both the Mac Pro and the Pro Display XDR, adding AppleCare coverage seems well worth it.
The $299 price point for AppleCare+ for the Mac Pro is the same regardless of whether the Mac Pro costs $6,000 or upwards of $52,000 with upgrade options.
AppleCare+ for Mac Pro and for Pro Display XDR extends coverage to three years from the date of purchase, and adds coverage for two incidents of accidental damage. There's a $99 deductible for enclosure damage or screen damage and a $299 deductible for other damage.
24/7 access to Apple's support staff by chat or phone is also included, as are onsite repair options, mail-in repairs, carry-in repairs, and global repair coverage.
AppleCare+ for Mac Pro is the same as the AppleCare+ plan that Apple offers for all of its Mac products. It covers the Mac Pro and its accessories.
AppleCare+ for Displays covers the Pro Display XDR, the power cord, one Apple-branded display stand, and one Apple-branded mount purchased at the same time.
The AppleCare+ protection policies for Apple's new hardware can be purchased when checking out. For the Mac Pro, Apple says AppleCare+ can be added within 60 days of a purchase, but there is no similar wording on the AppleCare+ for Display pages.