Use one big server
The author missed the most important factor why cloud is dominating the world today. It is never about the actual hardware cost. It is the cost of educating people be able to use that big server. I can guarantee you you will need to pay at least $40k a month to hire someone to be able to write and deploy softwares that can actually realize the performance he claims on that big server. And your chance to be able to find one in 2 month is closed to 0, at least in today’s job market. Also even if you find one , he can leave you in one year to some others places, and your business will be dead.