Till one point, when the business is so big, growing engineering team to over 100 is inevitable. But plently of really successful tech companies did not overgrow their team size for a number of years. E.g Facebook.
Human captial spent is actually the most expensive even comparing space rental if you add up salary, bonus, and benefits. I also will not recommend startups in their early stage (or even until they can break-even for a long time) to flu candidates over. There is really no reason to fly people over until you want to hire that person. Flying and hotel adds up big time too. Google can offer this because spending a couple millions doesn't matter to them.