Brokerage fee when selling individual stocks

It depends on the stock and the brokerage. Generally, if the stock isn't listed on the NYSE, then the brokerage will charge a commission on the transaction. Trust me, you don't want any other stock information from me.

What brokerage firm?

Companies that focus on managing assets charge anywhere from 50 yo 100 dollars a trade and then sometimes a small percentage. For example LPL, National Financial, and Raymond James all have divisions with Advisors working at a bank like say truist. They don't want to be in the business of self directed brokerage accounts so they charge a frickton to discourage that type of business. It eats up resources and isn't beneficial to the advisor.

If you want to buy and sell stocks go to a discount firm and place your trades online. Like TD Ameritrade or Schwab. It is typically free sometimes they have a really high dollar threshold where they may charge you something.

Even those companies where it is expensive to call in a trade it is much cheaper online. I think trades were 29.95 through National financial at the last bank I worked at. Pretty sure Truist's wealth management team cleared through them.