The most recent wholesale sales have been to Pacific Edge climbing gym and to the Park Service itself. So copies may/should be for sale at or through the gym and at both Pinnacles Visitor Centers.
I talked to a budding unicyclist near Seacliff today and he said the gym (Pacific Edge) is open again.
The Visitor Center on the west side is not open.
Copy and paste from the park website; (love the spelling)
East Pinancles Book Store
Open Thursday-Monday 9am-4pm
Run by the Western National Parks Association, this store sells all of the must-have Pinnacles souvenirs.
Phone
(831) 389-4485