Madmanlucky's page

It seems to be generally accepted that if a creature can cast a spell as a spell like ability, this has no material cost even if the original spell has a costly material cost.

Where does it actually specify this in the rules?

I was trying to find where this is stated and was unable to find it anywhere. This would suggest that unless a creature's ability specifies otherwise, they have to pay any associated material costs (costly or otherwise) any time they use a spell like ability (eg a bat creature that can cast fireball as a SLA has to, um yeah).

The CRB Magic chapter states:

Spell-Like Abilities: Usually, a spell-like ability works just like the spell of that name. A spell-like ability has no verbal, somatic, or material component, nor does it require a focus. The user activates it mentally. Armor never affects a spell-like ability's use, even if the ability resembles an arcane spell with a somatic component.

Universal Monster Rules states:

Spell-Like Abilities (Sp) Spell-like abilities are magical and work just like spells (though they are not spells and so have no verbal, somatic, focus, or material components). They go away in an antimagic field and are subject to spell resistance if the spell the ability is based on would be subject to spell resistance.