All painted from scratch in Photoshop CS5, using a Wacom Intuos 4 large tablet. I used the usual default round brush in photoshop, painting in the basic shapes. I borrowed some building images as guides and then completely painted over them, changing the structures entirely. The background spacecraft came together amazingly quickly for me - I blobbed in a rough shape and then painted in some hotspots to give an indication of form. The foreground character was improvised until I decided I had reached my artistic limits. This image is featured at raygun revival - [link]
This took about 3 days to complete. The cost for a similar image would be about £300 ($480).