The surnames Chowdhury, Talukdar, Sheikh, Pramanik, Mondol etc are common amongst the upper class but it doesn’t guarantee wealth, a person with such a surname could be dirt poor too.
Lower class poor could also have similar surnames or they may not have any surnames, surnames aren’t really that widespread.
People also have hasan, hossain, ali, osman, islam, siddik etc as surnames, these are common amongst all classes of people.
These aren’t the only surnames, there are many others especially amongst Hindus.
https://www.quora.com/What-are-the-surnames-of-Bangladeshs-lower-class-poor-people-and-upper-class-aristocratic-people