The Lost Omens line replaces the Player Companion and Campaign Setting lines from PF1. The price per page of Lost Omens is less than either of those.
Player Companion: 32 pages, $14.99 print, $10.49 PDF
Campaign Setting: 64 pages, $22.99 print, $15.99 PDF
Lost Omens (small): ~128 pages, $34.99...