d12 = 10x as many points as d4, but not even 3x as many HP from HD, a number which almost never even amounts to half your character's hit points, anyway.
Getting a +2 bonus to a saving throw from a class ability at level 4 is worth twice as much as getting a good base save as opposed to a poor base save, which amounts to a +2 to +6 bonus to the same save over time.
The ability to Turn or Rebuke Undead is just as expensive as having an Animal Companion.