How many trips exactly like that does it take to amortize the cost?

Modify your estimate for:
  • Multi-day trips
  • Trips to places with airports nearby
  • Times there more people travelling than will fit on your Cessna
  • Times multiple people are flying to different places
What is the pilot's salary?

Are there parking fees at the airport?

How about maintenance costs?

I don't doubt that a lot of people could fly GA cheaper than commercial, but I don't think owning your own company plane is likely to work for small companies. And in any case the calculation is a bit more complex than you presented.