It says the astroath can take 2 powers in the section for special character abilities. Does the astropath have to pay xp for them or just get them?

They're not required to pay XP for their first two powers, although they can spend the 500 starting XP to acquire more.

Errant said:

Actually they can't spend the starting xp on more powers. From the errata:

Note: The advances listed at Rank 1 are the two advances the Astropath receives free as starting Talents. When selecting these starting powers, all pre-requisites apply, and neither power can cost more than 200 xp.

So you don't have to spend anything to get the starting powers.