I didn’t know they were producing this, but it makes sense. Matches the other Absolute Editions.
Unlike the other volumes, this one is not numbered, so you can put it in front of the others or at the end, your choice. It’s a prequel, so first would make sense, though it was produced last, so last would also work.
The DC website has an on-sale date of June 27, so it should be in shops now. U.S. price is $125. Yes, very expensive, but I can’t think of another recent book that deserves this treatment more.