$50 · KRK Ergo Room Analysis and Correction System

This was gifted to me years ago by a leading American speaker designer and has never been used by me or, I think, him. It is spotless and complete with original packaging and papers and includes a calibrated measurement microphone. The CD with the operating manual was missing when I received this, but is available by googling "KRK Ergo software CD". This originally sold for around $500 USD, so the price I'm asking reflects the fact that I don't have the software CD and have never had this device in action, part of the reason being I'm not the most computer savvy person! It's also priced for quick sale.