8.25 million / 20 K per startup = 412.5 startups!
- Office space - Legal fees - Events (demo days, etc., are catered) - Salaries - Weekly food costs
I actually thought the operating costs would be slightly higher. The office is a comfortable space and the food is great(IMO, others might disagree :) ), the events are always well done, you'd expect the legal fees to be high, not to mention how much time everyone at YC puts in.