ASK HN - Good worksheet for estimating startup costs? (news.ycombinator.com)

I'm looking for pulling together some numbers for starting a tech startup (technical services at first - not so much a product company yet, but that shouldn't matter much) in the SF Bay Area. I've seen a few worksheets that are "fill in the blanks" but I'm looking for something that would say things like:

Salaries: $500,000 Benefits: (Usually 15% of salary) Rent: ($15 per square foot is usually a good estimate)

Seems like this is one of those things that should be pretty prevalent since many people have to go through the exercise but I can't really find anything very good.