The amount of time and money spent doing all the starting and running a buisness crap that has nothing to do with the actual work is staggering. I started my own LLC in an industry where I am considered an expert, and it was a complete failure in less then three years.
I had clients, I had projects, but was so overwhelmed with all the buisness elements I just couldn't spend the time required to get the work done properly. On top of that, while the money was good, the clients were often late paying, so all sorts of fees piled up and quickly ate into the profit. In the end I realized to do it right would have required at minimum four full time people.
Ended up taking a job with a large company as their in house specialist and I'm so much happier. I work shorter hours, get a regular salary with benifits, and spend my time doing the technical stuff I like.
Not saying don't do it, just be aware of everything that goes into it beyond the core elements of the work / product.