In Pride and Prejudice, Austen explores both how love is a conduit for, or a pathway to, marriage and how love is actually not a requisite for marriage.
Both Jane and Elizabeth are lucky enough to marry men who are both wealthy and also happen to be men that they love. Since the Longbourn estate has been entailed to Mr. Collins as the next male heir, it falls on Jane's lot, as the eldest daughter, to be sure to marry a wealthy man in order to ensure that both she and her family are provided for after Mr. Bennet's death. However, all throughout the book, Jane makes it quite clear that she cares more than about money when it comes to marriage. She wishes to marry a man she loves. Hence, it is a very exciting moment in the story when Mr. Bingley takes the Netherfield estate in their village and turns out not to just be handsome and rich, but, as Jane expresses it, "He is just what a young man ought to be ... sensible, good humoured, lively; and I never saw such happy manners!--so much ease, with such perfect good breeding!" (Ch. 4). However, when Bingley finally does propose, it's really not just that she loves him that gives her all the happiness she has. It's the fact that he is wealthy as well and that their marriage will bring relief to her family, as she states, "Oh! Lizzy, to know that what I have to relate will give such pleasure to all my dear family! how shall I bear so much happiness!" (Ch. 55). Hence, while love certainly is a conduit for marriage, it's not the only conduit, nor is it the most important.
Austen also shows us the unimportance of love in marriage with respect to Charlotte Lucas's choice to marry Mr. Collins. While Mr. Collins is recognizably a ridiculous man, Charlotte decides to marry him strictly out of practicality and financial security. Charlotte's father's fortune is not a large one, and Charlotte knows that in order to live comfortably in the future, she must marry. As Austen states in her narration, Charlotte neither thought highly of men in general nor of the institute of marriage, but well knew that "it was the only honourable provision for well-educated young women of small fortune" (Ch. 22). Not only is Charlotte's fortune small, she is actually described as plain and knows very well that Mr. Collins's offer will most likely be her only offer. Therefore, through Charlotte we see that financial security can actually be a stronger conduit for marriage than love.