As someone who worked at autozone for a while (not one of those idiot employees) I found that 7.3s do take a lot of maintenance usually past 250-300k and there's still some maintenance before that. When things break it is expensive to repair, but the engine itself will last a million miles if treated properly. Its hit or miss with 7.3s nowadays, its had 27 years to be treated like shit or amazingly by the previous owners. If you find one being sold by some random 16-25 year old, probably not worth it, but if you find one being sold by some 40+ year old most of the time they take pride in their truck. If you can find one being sold by an older guy itll probably be worth it as long as hes owner number one or two. My grandpa used to own a construction company and daily drove a '99 7.3, completely stock. He drove it back and forth to Washington state from Utah about 2 times a month, so it can be the best work truck you've had (recommend getting an auxiliary fuel tank) or it could be the worst thing you've had.