I have businesses which gave me a taxable income of $4 million. Mostly passive. All of them are tech businesses. Started off with a few foundational ideas I came up with through trial and error over 10 years.
I charge really high around $300 per month. That way you cut through the b.s. and it is clear you are delivering value or not. Also helps with the marketing as I can get more per customer than I spend on acquiring them.
Usually saas businesses all seem to charge really low like $10 / month for some reason. That is a mistake in my opinion.
There are lot of wealthy people in the world for whom $300 and even higher is nothing if it totally solves a problem.
I also provide human customer support because of that high price point so they like it if they have a problem.
Then I hired managers for each business who manage it for me and now it is almost a replicable model that I can use when starting any business.
I do agree that many SaaS services are underpriced (and many overpriced). SaaS entrepreneurs should take a bit more risk and try pricing their products at the higher end - even if its for an experimental duration.