Page 180 lists Rapier as having the Deadly d8 weapon trait, but the Deadly weapon trait description on page 182 states that a master quality weapon gets two deadly dice, and gives the example that "a master-quality rapier deals 2d6 additional piercing damage on a critical hit." I believe one of these numbers appears to be a typo.
EDIT: Forgot to state where on page 182 that passage is listed.