Expressions (phrases, clauses, etc.), Noun
(being) most satisfactory; (being) quite satisfied; (being) quite enough
Colloquial
少しの間だけでも一緒に戦ってくれるだけで御の字よ。Even if it's just for a short while fighting alongside us is all I could ask for.
Also written 恩の字【おんのじ】