from Series 4 Episode 24: The Collapse of the British Railway Sandwich System

Counter lady: Yes Constable?
Seagoon: I'm not Constable, I'm Seagoon: plain clothes man.
Lady: The what are you dressed like a policeman for?
Seagoon: I'm in disguise.
Ellington: Me too.
Lady: Mm, I can see that, yes. Now what do you want?
Seagoon: A mustard and cress sandwich.
Lady: Do you want bread with that?
Seagoon: No, I don't like luxuries.
Lady: Well you're out of it. I'm afraid we ain't got no mustard and cress.
Seagoon: How much would that be?
Lady: Let's see...mustard and cress sandwich with no bread, no bread with no mustard and no cress... one and six.
Seagoon: One and six for nothing? That's v cheap! Have you change for a 100 pound note?
Lady: Yes.
Seagoon: Marry me!