According to this rule I should be charging around $200 / hour. I would love to be able to do that, but I think your logic is flawed. I've found that multiplying by 1 or even less actually nets you more overall income after expenses (considering you get to expense some toys like that brand new macbook pro / air, ipad, etc.) for the year.

This is in Canada though, so I'm not taking the requirement to pay for your own medical insurance into consideration.