How much does it cost to have a wall and egress window professionally installed?

My husband and I have just bought a house, and we are hoping to turn part of our basement into a third bedroom. We would only need to have one wall added to completely close off the room (about 12 feet long) and do not need a door or any electricity or plumbing installed. However, we would need drywall installed in the whole room (12x12). We also are wondering how much it would cost to have an egress window professionally installed? Thank you so much for your help!