What are some SaaS ideas where clients will pay above $100 per month?

Pains that are worth $100/month. Start with a group of people, figure out their pains, whittle it down to only the most painful, and then start marketing to see if people would pay (and an estimate of how much they would be willing to pay).

No one has a list laying around full of new ideas that charge $100/month. Do the research.

Did you do some research yet? What are other SaaS businessees which are charging > 100 / mo

Those will be a good indicator what kind of problems are worth that ammount of money for the customers.

We are all looking for those ideas. Besides, in order to find the right idea for you it depends on where your skills and experience lie.

I could throw out some great idea that requires machine learning and if that's not your skillset, it would be pointless to try it.