Back when my previous 9-5 job ceased, Laurie and I had talked about trying to get a single plane/single pilot 135 going, either with one of the planes we owned or else with a plane we'd buy for the purpose. The business and demand were there. Very doable.
The problem came into the certification aspect. The local FSDO cited lack of manpower as a reason to not accept any new 135 applications, period. I could sign on with another 135 cert, but knew that was a losing proposition. So we dropped the idea, and I stuck to flying for other folks as well as my Cloud Nine work.
In the end, someone else decided to sign his Navajo onto that 135 cert I knew better than to touch with a 10 foot crankshaft, and it cost probably close to $50k and a year to finally get the plane, which wasn't in bad shape, to legal 135 standards and then get legal with check rides, etc. When I quit 135ing to come to my new 9-5, they no longer had a PIC and pulled the plane off the cert. As I understand it now, the plane's been sitting since about the time I left Pennsylvania.
Score one for government interfering with business.