Hello! You asked about the social class values and moral values in Jane Austen's Pride And Prejudice.
Austen's novel is set in the early 19th century. Remember that the American Revolution was fought between 1775-1783, and the French Revolution itself began in 1789. So, England in Austen's 19th century was fraught with change, influenced by two revolutions.
Social Class Values
The landed gentry like the Bingleys and the Darcys held most of the wealth in Austen's time. Strict inheritance laws provided for male heirs and concentrated power and wealth within select circles. Sons carried on the family name and power, and in Pride And Prejudice, the Bennett mother is desperate for her five daughters to make advantageous matches. Although Mr. Collins, the man who will inherit Mr. Bennett's estate, offers for Elizabeth, she cannot bring herself to marry the pompous clergyman just to salvage her future living. Mrs. Bennett is aghast at Elizabeth's attitude (more on this later).
Meanwhile, the newly rich trade/merchant class emerges, thanks to the Industrial Revolution. Members of this middle class (who have the money, but not the political clout or name) start to marry into the gentry. With the 19th century seeing landowners struggling under a heavier tax burden, England starts to see a more liberal attitude towards marriages between both classes. Jane's and Elizabeth Bennett's marriages to Mr. Darcy and Mr. Bingley are already indicative of the new changes affecting English society starting in Austen's time. However, the old aristocratic prejudice is difficult to extinguish; you can see this snobbish elitism in Miss Bingley's attitude, and to a lesser degree in Mr. Darcy's.
He really believed, that were it not for the inferiority of her connections, he should be in some danger.
Moral Values, personal versus social conventions.
In Austen's time, scandal might prove the death of a reputation or damage one's standing in society. When Lydia elopes with Mr. Wickham, the whole family is in despair. After all, a respectable young lady living sans marriage to a common soldier provides great fodder for gossip. Lydia's reputation is ruined, and any future opportunity for an advantageous alliance is forever closed to the poor girl.
Smiles decked the face of Mrs. Bennett...her husband looked impenetrably grave; her daughters alarmed, anxious, uneasy.
It was not to be supposed that time would give Lydia that embarrassment, from which she had been so wholly free at first.
Wickham allows himself to be persuaded to marry Lydia in exchange for money, which Mr. Darcy provides. You can see that daughters are not only the means to advance a family's situation in life; they are also expected to closely observe the strict moral statutes of Georgian society. Yet, Austen's Elizabeth Bennett presents a most incongruent example of maidenly decorum: although she is morally impeccable, she displays an intellectual curiosity and independent thought wholly antithetical to the average Georgian young lady. Mr. Bennett states that "Lizzy has something more of quickness than her sisters." So, Elizabeth Bennett embodies the Enlightenment ideals of John Locke, where reason and free will are considered greater indicators of one's success in life than mere fate. Hence, Elizabeth's personal convictions are juxtaposed against the social conventions of her time; she will not submit to Lady Catherine de Bourgh's demands that she refuse to marry Mr. Darcy, nor will she marry the pompous clergyman just because he stands to inherit her father's estate. She will marry whom she can love and admire.
Is the plot concluded with a moral?
In terms of Georgian morality, yes. Lydia's marriage to the scoundrel Wickham is portrayed as a matter of shame and embarrassment.
Hope this helps. Thanks for the question.