That's already more known unknowns than most software vendors have. 95% really boils down to "x licenses of package y, options z and w, additional support at n

That's already more known unknowns than most software vendors have. 95% really boils down to "x licenses of package y, options z and w, additional support at n dollars/hour", which you can put on your website just fine. The "sales teams" are often glorified speech-to-text lackeys that just feed your numbers to an excel sheet, read back the result and then make you believe you're getting special treatment. It's different for software that actually needs integration of some sort (SAP, most of the IBM portfolio, …) but SaaS startups doing this shit are just deluding themselves.