$3600/year is significant for a startup on a shoestring budget.
Or, better yet, don't use k8s. You don't need it, especially as a startup on a shoestring budget. You can migrate later if you decide you really need to, but just a plain LAMP gets you 99% of the way.
Around the time "Google Cloud Platform" became a thing, Google changed GAE from an encapsulated bubble into a basic frontend management system that interacts with normal services through public APIs (either inside or outside GCP). It's more expensive than GCE, but it's fully managed and lets you skip the devops team.
This makes it seem like Google Cloud for Startups is aimed at startups that aren't really on a shoestring budget.