You also need to find a person in an appropriate field. Not every field is easy for startups to break into.

Example, my partner is a nurse, but works in an office capacity. We've co-developed a suite of tools that make her job so much easier/faster. These tools could probably justify a $100k per annual seat and a small client might buy 20 seats. Yet, we can't really productionize it and sell it because healthcare is basically impenetrable.

So if your goal is to sell a product, think through sales and marketing before diving into the code.

100k per seat annually? Just to be clear, you’re saying that said software would cost roughly $100k/year/user? Is there any pure software product in the world priced that aggressively?

This is very true. The key is to avoid the classic "introduce a problem you didn't have so that you could solve it with a product".