- You must all be so rich.
- Well, we aren't exactly poor.

4 seconds sound clip from the Holiday (1938) movie soundboard.

You can hear this line at 00:09:42.095 in the Blu-ray version of the movie.

Quote context

[...]

- Do you want to know what happened?

- Mm-hmm.

- I went around to the kitchen door to ask for you.

- Oh, you didn't?

- I figured you were a secretary here, an old lady's companion. You sure you aren't?

- Cross my heart.

- What's that silly thing? Look at that.

- Oh, stop it, Johnny.

- You must all be so rich.

- Well, we aren't exactly poor.

- Julia, you should have told me, you really should.

- Would it have made any difference?

- Certainly. I'd have asked you to marry me in two days instead of ten.

- Aren't you funny, Johnny?

- Funny? Why?

- Well, to talk about it.

- It? Money? Why, is it so sacred?

- No, of course not.

- I'm simply delighted, that's all.

- If I suddenly discovered you could play piano, I'd be delighted, wouldn't I?

[...]