Peter Max and his $47,500 painting

Today, I spent most of my time at home and surfing my online world as usual. While i visited Ebay, i spotted one fine art on auction. My first impression towards this painting is shiny and cute, unlike the impression towards Vincent Van Gogh, Picasso, or Gustav Klimt. It looks like kids' stuff at first for me. Amazingly, the selling price is $47,500. (Oh my God) and one popped question is who is the artist?, Well, he is Peter Max.
I have no idea at all who is Peter Max until doing some research. He is a well-known pop artist, born in Berlin, Germany then settled in the US in 1953. Max's art work, which he called "up art," was a part of the psychedelic movement in graphic design. His work was influential and much imitated in advertising design in the late 1960s and early 1970s. I also found his official website. His works are unique and colorful and i never thought that his painting can be sold expensively. The below are the example of his works. "If I didn't choose art, I would have become an astronomer," states Max. How about you? If you didn't choose advertising, what would you be?