I have 3
03 F550 4x4 with the 6.0. 175k miles. It has several toys like Banks exhaust, tuner, intake and so on. I have replaced injectors, fuel pump, ficm over the last two years.
03 F250 4x4 with the 7.3. 250K miles. Banks exhaust, tuner, intake. Replace one injector and fly wheel.
01 F250 4x4 with 7.3. 275K miles. Completely stock. Replaced one injector, injector harness. It's a little tired but goes everyday.
In summary
2014's are $75k which is crazy.
7.3 are unstoppable but at least 11 years old now. You can find them with low miles for $15K to 20K when a retired rv'er trades up. For about 10k you can rebuild the drivetrain back to better than stock.
6.0's are readily available and cheaper than the 7.3's. With a good mechanic you can make them reliable for about $7k. EGR delete, head studs, ect.
6.4's were a problem child from the beginning and did not last long. I would stay away from them.
6.7's have a few problems but they are quiet and powerful but it will take $35+ to get in one.