Vow of Poverty Necromancer
Tricky, but not impossible. I assume you're talking about the army of the undead sort of necromancer, otherwise it's not even really an issue. A 2-level dip in Pale Master costs you 1 caster level, but also gets you 1/day
animate dead without the need of a material component. If you're willing to settle for zombies and no skeletons (or obscure other things you can make with
animate dead), you don't need Pale Master, instead just kill things with Fell Animate spells (preferably Fell Animate necromancy spells, so your Corpsecrafter feat line applies).
If you're doing the Pale Master thing, you'll need something with a non-good alignment subtype or other way to qualify for the class while actually being exalted.