Total cost of ownership will overwhelm the slight differences is speed and fuel flow. If you want to save money take the airlines it will always be cheaper.
My advice and worth every penny you paid for it
is buy what you want, not what you feel will be the best value.
It is the intangibles that will give you the true satisfaction of aircraft ownership.
If you are buying used do your homework and IMO buy the very best example of your chosen airframe, it will be the cheapest in the long run.