Making $20 million a year SaaS companies into $22 million a year SaaS companies. If you have reasonable expectation that I can actually deliver on that, then you're pretty much willing to say yes to any rate I quote.

If you're curious "How does one turn a $20 million a year SaaS company into a $22 million a year SaaS company?", there exist many options depending on the specifics of the company and virtually all of them are doable. For example, if you increase the rate at which the SaaS company closes deals by a modest amount, that could reasonably hit that by itself. You could do that by some combination of A/B testing, better email marketing, tweaking sales processes, etc, alone or in combination. I've blogged pretty extensively on all those topics if you're curious.

These are not necessarily all that technically complicated. If you can figure out ActionMailer, an if statement, and a for loop, you have every technical capability you need to be an engineer in charge of email marketing. The interesting bits are "What emails do I decide to send?", "What words go in those emails?", and "What goes in the if statement?"

The actual work is exactly as dominated by meat-and-potatoes execution ability as you think it is.