Pro
Pro is in preparation. Core is the edition that ships today.
Pro is not ready
We are not going to describe an edition that does not exist yet, or put a price on it before we can defend it.
Pro is intended to add an optional integration layer, for equipment that does not speak Zigbee and for people who already run something else at home. The hardware is a more capable board than Core uses.
What ships today
Core. The hub, Zigbee, the floor plan, the device registry and electricity metering — everything described on the Core page, working now.
Core and Pro share the same software and the same release train. Nothing bought today becomes obsolete when Pro arrives.