Hey - I'm the author.
And this is exactly right - it's all the work that goes 'around' the billable time, which is the real time suck. Also factoring in that this was my first full-time experience and so, since I was determined to get really good at what I was doing, I was also trying to learn as much as possible end expose myself to as much new stuff as I could.
You get major economy of scale by the time you reach Step 5, in terms of admin time costs (accounting, invoicing, legal fees) but at Step 2, you're doing it all yourself, and learning as you go along. A real killer.
It's £30, rather than $30, btw. Minor clarification, doesn't change the relative calculation, of course.