Economics play an important role in how the plot develops. The Bennets are not poor, but they are not comfortably wealthy. The Bennet girls do not have pretty, fancy dresses to wear like the Binghley sisters. Their home, Longborn is nothing special, it is a comfortable home with a few servants, but they do not live a life of total leisure.
Economics play a part in why the match between Darcy and Elizabeth is so unlikely. She is beneath him socially and economically, so technically, she is not eligible to be his wife. Even though Elizabeth is a gentleman's daughter, and can expect to marry well, some rich families, like Darcy, look down on less well off people as looking to expand their financial position by marrying money and are scorned.
Mr. Collins lives a humble life as a minister, but is constantly at Rosings, the palatial home of Lady Catherine Debourgh. He talks about Rosings as if it should be worshipped like a religion. Wealth is an insulator, rich people in the book can say anything they want and they must be respected. When Elizabeth speaks her mind, she is considered an insulent girl.
Wealth is admired and creates awe in others. Mrs. Bennet talks about the incomes of others constantly, as if that is the true measure of their individual worth as people.
In 19th Century England, it was not only important that a family have a good reputation. Money was then, as it is now, of vital importance. For example, the Bennet family is a respectable family. Elizabeth declares to Lady Catherine that she [Elizabeth] is "a gentlemen's daughter". This is very important in making her eligible for a good marriage. The daughter of a gardener could not expect to marry anyone from a gentlemen's family, but a gentlemen's daughter has a good chance to marry financially well.
However, Mr. Bennet did not put aside dowries for his daughter's. He had a good estate, and should not need to. But because the estate would not be kept in the family, there was fortune for the girls:
"When first Mr. Bennet had married, economy was held to be perfectly useless, for, of course, they were to have a son. The son was to join in cutting off the entail, as soon as he should be of age, and the widow and younger children would by that means be provided for."
The early relationship between Wickham and Elizabeth shows the result of this lack of economical management. Her Aunt Gardiner warns Elizabeth against the match:
"I have nothing to say against him; he is a most interesting young man; and if he had the fortune he ought to have, I should think you could not do better."
Clearly, all the characters, even of equal social class, must be concerned with fortune and economy.
Jane Austen belongs to the Romantic Age in English literature.
"Pride and Prejudice"(1813) like all of Jane Austen's novels reflects faithfully the socio-economic conditions of what historians term as 'Regency England'(1811-20).
Since women of this period had no right to ownership of property they were financially dependent on their husbands,and hence the urgency and anxiety throughout the novel for the ladies to get married to "young men of large fortune" (ch. 1).
Mr.Bennet's estate is 'entailed' to Mr. Collins because Mr.Bennet does not have a son. In 'Regency England' only male heirs could inherit the title and the estate of their fathers. The third paragraph of chapter 50 clearly reveals the 'economic' necessity of having a son and the disappointment at not being able to have one and the consequent predicament which Mr.Bennet faces in not being able to personally meet the financial demands of Wickham.
In Ch.33 Col.Fitzwilliam tells Elizabeth "I may suffer from the want of money. Younger sons cannot marry where they like." clearly hinting at her impoverished status.
The central theme of the novel--how much money is necessary for a successful and a happy marriage--is explicitly stated by Elizabeth in in Ch.27 : "Pray, my dear aunt, what is the difference in matrimonial affairs, between the mercenary and the prudent motive? WHERE DOES DISCRETION END, AND AVARICE BEGIN?"
Was Col. Fitzwilliam Darcy 'discreet' or 'avaricious'?