I have heard that there are people who sell domain names while charging a nominal commission. Please let me know if there are some expert people who do this regularly
Well this depends on various factors, domain age, name, if is too old need make sure if is not in blacklist, etc.
Those man is called Broker. You can search them in DnF or any Domain forum. You need to have decent domain which can be sell to the end user.
They are known as domain brokers. But don't waste your time with them unless you have premium domains.