A medium to very large company will spend $0.95 to save $1.00. Because of tax incentives and business performance metrics, any opportunity to grow for the future is usually capitalized on so all you have to do is find a pain point for a company and pledge to solve it cheaper than they can, which is usually through headcount.
In fact, an easy way to find ideas (to the point where it kind of feels like a cheat code) is to see what companies in a given industry are constantly hiring for. If you can replace 10% of a job that companies pay $65,000 per year per head, you can pretty easily demand $6,500 or more. Unlike a W-2 employee, Your company does not cost your customer a full-time manager, nor does it increase administrative burden for HR, IT, or facilities, and does not incur costs such as benefits, payroll taxes, or accounting fees associated with personnel - which will undoubtedly be higher than the flat monthly or yearly line-item on the expense sheet that your business represents.
Choose an industry, pick a pain point, build the product, price it according to what it costs, and sell to them. You typically won’t find super interesting problems to solve here but it will be reliable as long as they don’t build it themselves.