Exactly. The reason Linux and Windows did so well was because they ran on $5,000 server quality PCs, whereas IIRC SunOS ran on a $20,000 workstation, and AIX on a $60,000 workstation. The takeover of Linux and windows was more because of the ability to run on cheaper hardware than being a better OS.
I contracted at IBM Federal Systems when it was sold to Loral, and the first thing we did was dump the AIX systems for Sun, because of the price. Not because Sun was better than AIX. I personally thought AIX was better than Sun, but not worth that much of a price difference.