Is $100 / hour too much to ask for a Senior C# Developer in San Francisco?

Hi.

An agency is considering me for a contract position in San Francisco. It’s a senior .NET role with healthcare company that will probably include leading a small team of programmers.
Right now, both .NET and healthcare are hot on their own, but together are a bit rare.

To get my contract rate, I usually divide my expected compensation (salary + benefits) by my billable hours. Usually, this number comes to 1 / 1000 of expected salary.

How reasonable is charging $100/hour as a Senior .NET Developer with architecture skills in San Francisco?