Not to say that frivolity is good and frugality is always bad. But it shouldn’t be an obsession.
As an employee I would much rather work for a company with soaring revenues than one with quickly decreasing costs :)
Cost and revenue are not related like that. You're thinking of profit margin, but even then it's not that simple. Most expenses can be written off, but profits are taxed. Revenue can be increased by spending, by adding features that increase demand, or just by plain advertising. You can have high profit margins but low profits due to low revenue, all because you cut spending.
Moreover, for a new company, being profitable is far less important than (an expectation of) growth. A mostly unprofitable company like Tesla has incredibly high expectations of the future already priced in.
There was a post on HN recently about a SAAS that listed out all of the SAAS products they were using, and for a team of 5 they were purchasing g suite, an email productivity "enhancer" to avoid conversations moving to slack, and a meeting scheduling tool, for 10% of their revenue (something like $150/month). Being frugal would likely have cost them less than percentage points of productivity, and increased their runway.
The cost of a kubernetes cluster while working on an MVP is not a unit cost. It's a development cost. If they don't even have the MVP yet, then I don't think it's fair to say they're going to pay a multiple of that kubernetes cost for every sale - I could be wrong of course, the details matter.
Your second example to me seems more clearly totally fine. Those costs scale with the number of employees, not with the number of sales. If their sales scale linearly with their number of employees, they are totally screwed under the VC funding model. As somebody upthread said, frugality is important for traditional businesses, but not so much for software-y startups.
$150/month is peanuts for their runway almost certainly, too. Think about it this way: even at a meager $50k/employee/year, their costs are 99.3% in the employees, and 0.7% in those software products. Or think of it this way - $10k will cover the $150/month for over 5 years, which is a really long time.
Love this.
The one caveat though, and why it's important to keep costs low (maybe wait until after you sell the startup), is because when you are profitable, then you are in control of your time and get to set your own schedule. Or, in the form of the above quote: your revenue can go up to infinity but your time left is capped at 100.
This presupposes that you can get to high marketshare profitability while keeping costs low. That's not always realistic. A more growth-minded competitor can push you out of the market entirely by willing to execute where you won't.
It hadn't yet crystalized in my mind but to clarify my advice is keep your personal cost of living low as a rule of thumb. Optimize for free time over more money.
For business, spending money is essential. Ideally try to spend other people's money.