SOLVED. It is about a woman who is looking for a rich guy to get married with. She is elegant and beautiful. Lives with her aunt who takes care of her expenses. There is another guy in the story who is not rich but he also likes this woman. [s]

[Samiksha]

The plot is something like this:
It is about a woman who is looking for a rich guy to get married with. She is elegant and beautiful. Lives with her aunt who takes care of her expenses. There is another guy in the story who is not rich but he also likes this woman.
Because of the woman's lavish behaviour her aunt passes on her wealth to her cousins. The woman's friend's husband starts giving her money on the pretext of having profits in a business that she is also "part of". But later the woman discovers that he has been lying to her and by giving the money he wanted to force her to have an affair with him.
By the end of the novel, she becomes very poor and sick. She is badly in debt and needs to return the money. The guy who loved her tries to help her. But in the end of the book, she dies.

As far as I remember, the story is about lives of upper middle class British in 20th century. It talks about the extravagant lifestyle of people and the struggles behind it.

[Cycad]

The House of Mirth, by Edith Wharton?

[Kris]

The House of Mirth by Edith Wharton - Cycad's suggestion

[Lobstergirl, au gratin]

Samiksha, as indicated in the popup box which you hopefully saw when you posted your first comment, please put genre and plot details in your header. This helps people searching for your book, as well as anyone in the future looking for the same book.

[Samiksha]

Yes, it is this one. Thanks a lot! :)