But how would this compare if you had upgraded, let's say the F16 and F18, to have the same avionics and weapons systems capabilities as the F35? Or is that impossible without an entirely new triple-gold-plated air frame design?
F-16s and -18s aren't without their flaws either, and aren't stealthy at all.
"In the year 2054, the entire defense budget will purchase just one tactical aircraft. This aircraft will have to be shared by the Air Force and Navy 3½ days each per week except for leap year, when it will be made available to the Marines for the extra day."
but Law Number XI might apply to this audience the best:
"If the Earth could be made to rotate twice as fast, managers would get twice as much done. If the Earth could be made to rotate twenty times as fast, everyone else would get twice as much done since all the managers would fly off."
x: http://aviationweek.com/defense/next-100-years-norm-augustin... (paywall)
You are talking about replacing basically everything except the aircraft frame. A frame which is using decades old technology and lacks any form of stealth. And given that the entire point of the F-35 is the deployment of sensors within a contested environment not sure what the point would be.
F-16C Block 70 Viper II is about $80m each, so not much under a F-35A
Bear in mind that that's not the same type of price you're quoted when buying a car.
The weapon system program includes the cost of training technicians to maintain and fix it, training pilots to fly it, the projected cost of expected mid-life upgrades, and most often overlooked is the cost of disposing the airframes when they are to be replaced in the future. You can't just put it in a landfill, it's loaded with highly classified military equipment.
But, but, but...!!1 Now that they are in the field producing results the haters begin retreating to ever smaller and more qualified hypotheticals. I'm pleased with myself for not having participated in the stupid F-35 flame wars that have been raging for years with these people.