It not the cost of the purchase. It’s the cost difference between part 135 and part 91 certification and maintenance that is the only real consideration.
Rich people buy buy expensive toys all of the time, and some of those put the aircraft on line to pick up some hire work. When I was instructing at Moorabbin the school had half a dozen Warriors, but there was always a privately owned Lance or Cherokee 6 on line for hire.
The bulk of that work was instructing, but I also did a few single engine charter out to places like Bendigo and Merimbula for businessmen (we’re not talking the CEO of CocaCola here, but builders and carpet store owners) because getting out and back in a day made more sense for them than driving four or five hours each way and spending a night. Being able to do that IFR would have been nice, and with a Cirrus that is possible, because of the avionics setup (in the USA at least).