For a long time I never understood cubism and why some of its art is so expensive. This following excerpt helps explain why it developed but still doesn't answer why it's so damn expensive. If you do want an explanation, check out some of my previous excerpts on contemporary art:
The aim of cubism was not to reproduce visual reality but to record a response to an object - whether still life, landscape, or individual - that was developed over time and was both visual, in reflecting different angles of vision, and intellectual. What was important was not the sitter as he appeared to the world but the painter's conception of him. Kahnweiler likened the process to that of poetry, quoting the French nineteenth-century poet Mallarmé, who claimed that his poetic goal was "to describe not the thing itself but the effect it produces." Once photography had freed painters from the obligation to create a likeness, they could abstract the portrait in a variety of ways.
Pablo Picasso - Daniel-Henry Kahnweiler (1910)
In order for the artist's subjective response to be considered the most important aspect of a portrait, it was necessary for a change to occur in the circum stances in which portraits were made. In previous centuries the relationship between sitter and artist had been dominated by the sitter: it was the sitter (or the person commissioning the portrait) who dictated how the sitter was represented, and it was the sitter's self- image that the portraitist was employed to convey. But when artists, represented by dealers, began to paint almost exclusively for the open market, portrait commissions gradually became less important to their financial survival. Since the late nineteenth century artists have been increasingly able to choose whom they paint. (Picasso's portraits were almost all of his friends, wives, lovers, and children.) Today when some one commissions a portrait from a leading artist he or she usually does so on the understanding that he or she will submit uncomplainingly to the artist's vision.
Abstraction in portraiture - which results from the imposition of the artist's own personal vision on the sitter - has many sources, but it always depends on the artist being seen as the more powerful partner in the transaction. However, when looking at portraits it is as well to remember how recent such a view is. Today we may remember Mona Lisa only because she was painted by Leonardo, and Mr. and Mrs. Andrews simply because they had the foresight to ask Gainsborough to portray them, but at the time they would have had no doubt that it was they who were calling the shots.
Pablo Picasso - Les Demoiselles d'Avignon (1907)