If I'm not mistaken... then Komolika was a rich lady. Mohini in the very beginning of the serial believed that upper class should marry only upper class people. Which is why inspite of knowing about Anu & Prerna, she got Anu married with Komolika. Which makes Komolika to be upper class women which mean she was rich or atleast her mom was rich!
Now I wonder if Basu khandan was as rich as Bill Clinton in the tv serial. Wonder what would Bajaj be then, since he was much more wealthy than Basu's back then!!