Speed Painting - took about 4 hours. I started this as a demonstration of digital art at a recent sci-fi convention in Bath, UK. This image is a personal project, so doesn't belong to anyone else, i.e. a client. If you wish to use it, please contact me first.
I got home and finished it off.
All done in Photoshop CS5.
To create an image like this from scratch will probably take a day, including revisions. The cost would be £120 ($200). This is a very loose concept, not a high res illustration.