A portrait is a commissioned work of art. It is not just a painting of a face or of a group of people. The buyer usually gets involved in design decisions.
I have not at this time been asked to make a portrait, but I am interested to paint portraits also. If you like my style of painting, and would like to commission a portrait, give me a call. I would have to make a full assessment of your requirements before I can provide you with a price estimate.