Finishing an immersive master is mostly about delivery. One ambisonic master becomes a binaural file, a 7.1.4 stem, a lower-order version for a game engine — and each has to hit its number and stay under its ceiling. These are the tools that check and protect every one of those versions from the one master.
Bought one by one: €592. In Mastering: €379. And the free ones, Encode, Downmix, View, Depth and Beacon, work with all of it.
Step up to Total: €520 more, for 22 more plugins. If you already own Mastering, that is all it costs you — what you paid counts in full.