$750 x 21d x 12m = $189K
Do you think $189K per year is an average salary? It is not true.
Do you think $189K per year is an average salary? It is not true.
Also, for the skills implied, have you ever tried to hire a systems administrator who has experience in production environments with all of those aspects of back-end web servers? It's not easy, and it's not cheap.
But Boston is Boston, and SV is SV, and this is estimation, so I'll happily concede a factor of two. Okay. Suppose $750 buys you two engineer-days per month. Same question: Is the $750 important?