What are the factors which influence their choice of their life partner of the marriageable Bennet daughters in "Pride and Prejudice?"

'Romantic love' is the central theme which unites all the incidents and the characters in "Pride and Prejudice." But there is nothing 'romantic' about Jane Austen's treatment of 'romantic love' in the novel. 'Romantic love' is checked and controlled by the incomes and financial freedom of the partners involved. 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).In this manner Jane Austen is able to blend 'romance' and 'realism.' For example, Lydia and Wickham who elope 'romantically' have to be rescued by the generosity of Darcy before they are married.

The restraining power of money on 'romantic love' is spelt out in the thematic statement found in Ch.27, "Where does discretion end, and avarice begin?", when Elizabeth replies to her anunt's query concerning Miss King the latest lover of Wickham. Her aunt is relieved to know that Elizabeth is not in love with Wickham who has virtually no income at all and is only employed temporarily in the Militia.

Money no doubt is certainly necessary for a successful and happy marriage. But the vital question is 'how much?': In Ch.33 Col.Fitzwilliam Darcy,the younger son of an earl,a very rich charming young man,subtly hints that he cannot marry Elizabeth:"Our habits of expense make us too dependent, and there are not many in my rank of life who can afford to marry without some attention to money." to which Elizabeth playfully sugggests that his price would perhaps not be "above 50,000 pounds."

In Ch.19 Collins threatens Elizabeth to submit to his proposal by emphasizing her impoverished status:"one thousand pounds in the 4 per cents, which will not be yours till after your mother's decease, is all that you may ever be entitled to."

The novel is a heart rending cry for the freedom of young women from the clutches of mercenary men who toyed with their happiness,as Charlotte tells Elizabeth in Ch.6:"Happiness in marriage is entirely a matter of chance."

Another important consideration in love and marriage was the social class to which  the characters belonged:

At that time, ownership of land and not money was the single most important criterion which determined the social status of an individual. Lady Catherine tries unsuccessfully to dissuade Elizabeth from marrying Darcy,because she is poorer than him but Elizabeth angrily retorts: "In marrying your nephew, I should not consider myself as quitting that sphere. He is a gentleman; I am a gentleman's daughter: so far we are equal."(Ch.56).