The series is worth the money. It is not out-of-print - pitty because wished they continued the collaboration of writers. A new author: S.G. Rainbolt (author of Dear Sun, I Am Real) flirts with the other aspect of the Laws of Robots, this time it is inside the actual digital mind (the webbing between the human mind and the computer world). That too is worth the read.
I love these books, I started reading these when they first came out many, many years ago. Read the entire Robot City series but never got the chance to finish the Robots and Aliens series. Awesome story with lots of twists and turns. Loved that they used many different authors and gave them a chance to show what kind of writers they are.