I've never paid more than £3 for a Systema class. The most expensive seminar I ever Systema seminar I paid for was £20. That said I have no doubt there are people out there making a lot of money teaching.
The Systema breathing taught me to alter my breathing rythmn depending on what was happening around me or how I was feeling internally. Some times slow deep breathing, other times sharp fast exhalations. Depends on what was going on. Never came across that before. Prior to that Yoga breathing and the Japanese breath work in Aikido always taught to breath in a universal way, regardless of what was happening. The System taught that that wasn't always apparent.
"Let your food be your medicine, and your medicine be your food"