“She paid for the trip out of her own pocket.”
You're daughter's school club went on an overnight trip. You're concerned for the teacher, who paid for her own hotel room and food. You're talking with one of the other parents about it. You say this.
She paid for the trip out of her own pocket.
Paying for something "out of your own pocket" means that you pay for it yourself, rather than having it paid for by someone else. You especially use "out of ___ own pocket" when:
- someone pays for something that should have been payed for by someone else (like in the example above)
- someone pays for something that's really expensive and hard to afford. For example:
A few notes: people can only pay out of their own pocket. It doesn't make sense to talk about paying out of someone else's pocket. And it's always singular "pocket", not "pockets".