Where an artist is in his/her career may (should) dictate pricing of artwork. An established, award-winning, recognized artist's work will generally be priced by demand. The price is determined by what buyers are willing pay for the work and competition for limited output may push this along depending on the collectibility. For the rest of us, we use a few methods. One of the most popular for starting artists is to price by time & materials. This method takes the artist's time and adds a numerical value to the hours of work going into a piece and then covers the cost of materials used to produce the piece. Emerging artists, for this purpose I'm referring to artists who have sold work and who are starting to get more attention, may also use this method and then add a premium which will usually increase as his/her popularity increases.
There are also artists who arbitrarily price their work. It may be based on how emotionally attached they are to the piece or a number he or she wants to get at that moment. Scary but true! Other more methodical artists look at the market, comparing their work to other work being produced by artists similar to them or to whom they aspire to be compared, and then price their work to follow.
Most artists do strive to be consistent in the pricing of their own work and you may be able to detect a pattern by reviewing that artist's portfolio of work along with the pricing. There are times when the size, complexity, originality, or even the simple genius of a piece will dictate the pricing so don't be surprised when a small, detailed oil landscape outprices a wall-sized floral in the same medium or when the price of that landscape pales in comparison to a simply stated abstract with two straight black lines intersecting on a white background.
It's generally not polite to ask an artist how he or she sets prices but it's perfectly okay to inquire as to whether he or she would consider $X amount for a piece. As long as the asking price and your offering price is not too far apart, the worse that can happen is that he or she says no and you've lost nothing for asking.
vivian leflore mora