SACD Creator wasn't designed for the average music fan. It was a high-end tool for mastering engineers and replication plants. Its price reflected this professional status. A dedicated software package for a niche format was never going to be freeware. Even when Sonic Studio announced cost reductions, the savings were to make it merely "less expensive" for professionals, not to turn it into a free download.
While mostly a player, the SACD plugin for Foobar2000 allows for the conversion of DSD files to various formats and, with advanced configuration, can assist in creating images. How to Create an SACD Image (DSD to ISO) sonic studio nexstage sacd creator free
: The original nexStage SACD Creator was primarily designed for Windows 2000 and XP environments. The Search for a "Free" Version SACD Creator wasn't designed for the average music fan
Below is a blog post exploring why this software is so elusive and what you can use instead. A dedicated software package for a niche format
The Ghost in the Machine: Searching for Sonic Studio NexStage SACD Creator