There is a chicken-and-egg problem with defining your mission in general aviation. Flying your mission is the only good way to fine-tune what kind of airplane and ratings are necessary and appropriate. But you can't fly your mission if you don't have a plane capable of doing it. The normal route is to work your way up and redefine your mission as you go. You might find that your trips are often taken solo, VFR, to a distance of 200 miles, at 5,000 feet. Flying that trip with an M350 is like commuting to work in a motorhome. You would be spending a lot of money on fuel and maintenance to haul around a bunch of empty seats at an altitude where pressurization is basically meaningless.
That's not to say it's not a great plane for that trip, it just is not the most efficient choice. A Piper Arrow that costs 1/20 the acquisition price and much less in fuel and maintenance (not to mention insurance, the original topic of this thread), will take 1:32 to fly those 200 nautical miles when the winds are calm. The M350 will take about 1:04 for the same trip at a similar altitude. The Arrow will burn about $70 in fuel while the M350 burns closer to $125. Are your trips and your time so valuable that 32 minutes are worth 20 times the capex, probably 5 times the maintenance costs, and nearly double the fuel costs?
If you can afford the pay cash for a new Piper M350 or M500 and you're serious about buying one, you should be able to convince them to give you and some members of your family a demonstration ride in one. You might find that you all hate the plane or that it is a bad fit for your mission. Or you might find that you love it and that it's perfect for your mission. Then you can buy one and pay a CFII to fly with you for the first year or two.
The step-up options are probably better for most people, though. The cost of buying an M350 or M500 and hating it is much higher than the cost of buying a PA-32R and deciding to upgrade, even without thinking about insurance. Getting your instrument rating and 400 hours in a PA-32R will make you much more insurable in the bigger Pipers, and you can fly your mission in a PA-32R. Frankly, I find the PA-32R more comfortable than the PA-46 as a pilot and I'm not sure there is much difference for passengers. It's mostly a question of speed, as far as I can tell.
Consider this: JFK Jr. was happy to upgrade to a PA-32R for his mission. I don't know about your net worth situation, but I don't think the Kennedys have traditionally made decisions based on the price tag. So, even if money is no object, the PA-32R might be a better fit than the PA-46. Food for thought.