Prices for oil paintings, pastels, and drawings are so variable because the content, size of canvas, or medium etc. can be so diverse.
Two paintings of different size, featuring the same person with different dress, backgrount (abstact or complex) or style of painting can take various degrees of time.
So to specify one price for all is impossible and very misleading.
These generalised figures will give you a starting point from which to work.
Drawings from £150 12" x 16" Head and shoulders
Pastels from £200 12" x 16" Head and shoulders
Oil on canvas from £350 12" x 16" Head and shoulders
An example of a much larger canvas 24" x 30" including Head shoulders and hands would be £800
May I suggest you telephone or e-mail me and I will do my best to accommodate your portrait requirements at a price and time-scale to suit you, with no obligation.
See contact page.