Contrarian view: don't spend time automating things. Spend any extra time you have selling and building the product people need. If someone needs your product, they'll probably be fine with an invoice. Spend the early mornings before work prospecting and reaching out to potential customers. If you're on the west coast, even better because you can conduct sales calls with east coast people who are already at work. Aft…
Yet, I believe that you are absolutely right. We should fight our inclination to see everything as a nail for the hammer that we master. The ROI on automating everything from the outset is not worth it, and if the business flops, it's just wasted effort. Worse yet, it's a missed opportunity for learning about the customers and about the domain.
So yes, do things that don't scale. If and when you get in the air, profile the business processes and only then automate the bottlenecks. It's the only sane way when you think about it.