After four months of only being available to iMac Pro owners, the Magic Keyboard with Numeric Keypad, Magic Mouse 2, Magic Trackpad 2 are available to all.
Apple originally said that the trio of peripherals would only ever be available to iMac Pro owners, and then, only at the time of original purchase or as a service replacement. The availability today stands in contrast to that, and will likely sink the healthy resale of the peripherals on eBay and similar venues.
At present, it is not clear if they are limited to the Apple online store, or will be available at Apple retail locations after the new iPad arrives.
As expected the Magic Keyboard with Numeric Keypad in Space Gray is $149, with the Magic Mouse 2 selling for $99. The Magic Trackpad 2 retails for $149.