You're making the mistake of assuming everyone has the same problem as you do.

Pre-SaaS most companies would have paid upfront for a piece of software (before knowing if it works for them) and then upgraded ever few years in any case. For multi-user software they would have needed to pay for servers, ops staff, etc. on an on-going basis in any case.

When companies are evaluating a SaaS solution versus a boxed solution price is not typically a major deciding factor.