IMHO you need to disassociate Sugni from Chulbuli until you know that it is Sugni.
If assume that Chulbuli is a different person that happens to look like Sugni then think about the setting she is in you may find that you have misunderstood what she saying.
Chulbuli is living in a den of prostitution. She is practicng dancing wearing gungaru.
Her comments was Tell my seth to come and take me away in his big car... and later says I will earn Amma more that the whole street, Bihar and UP.
I think Chulbuli has accepted her fate that she will become a prostitute. She is not fighting it. She is asking Amma to find a rich man who will pay a lot for her and hence her comment about earning more money for Amma than anyone else.
TVS is looking for redemption. He is tortured by the knowledge that his actions have resulted in Sugni's death. His redemption is not going to come from falling for Sugni lookalike.
Would his redemption not be to teach/support this girl who has accepted her fate to have a different dream one of living a life of dignity and then fight for that dream? ie. improve her life like Sugni wanted to improve hers. And I don't mean improve her life by marrying her.
This is no longer a love story. Its about doing the right thing. After all life is about more than love,
So for the time being until you know otherwise accept Chubuli at face value and then why not sit back and enjoy what is being shown and see how it unfolds rather than constantly worrying about what may happen.