Your question is not black and white or true and false, it is complex.
A C5 should last well into six digits on the odometer even with the once in a while full throttle
check. The body will never rust. Oil changes, tires, exhaust, battery, brake pads, maybe a few bulbs here and there and the annual air filter should be all the car requires.
When we were looking at used Vette's there were many and some had been treated well and taken care of and some that were not. Mileage on a vehicle is relevant to the maintenance the car receives. But when buying a used vehicle, if you are not a mechanic, I recommend finding one that you trust and have them give the car a once over.
Car fax helps but you have to know what you are reading and also understand that a car fax reports on insurance claims only, not necessarily every incident involving the vehicle.
I suppose it is not the direct answer you are looking for but.......................