“A single man of large fortune; four or five thousand a year. What a fine thing for our girls!” In “Pride and Prejudice” Jane Austen did not have to explain to the 19th-century reader what Mr Bingley’s “four or five thousand a year” meant, or why it excited Mrs Bennet. It was obvious. Mr Bingley was an heir. And the surest way to get rich was not by working hard but by marrying the right person.