Some chick to Churchill: If you were my husband I would poisen your tea.
Churchill: If you were my wife I would drink it
The "chick" in question was Lady Astor, the first woman to take a seat in Parliament.

She and Churchill didn't get on, it seems, since this one is also attributed to them:

Astor: "Winston, you are drunk"

Churchill "And you, madam, are ugly. But in the morning I will be sober."

I might be wrong but I thought the one about the price was Bertrand Russell