Welcome to orangetractortalks! This is a terrific site, with some very friendly, knowledgeable, and helpful people.
I think, possibly, some people have varying tastes in what is acceptable or what is not. I don't own a single tractor (out of 12 plus some lawn/garden stuff) that has nice paint, seat, or body panels. They have all been honestly worked; I use them for that myself. Work means sometimes I have to lay a chainsaw, toolbox, or parts on the hood of the tractor. Sometimes tree limbs fall onto it, or dirt from a bucket. I haven't had covered storage for very long; not all of my stuff will fit under it anyway.
Some of the tractors are leftovers from my family's earlier farming days on the desert of Arizona. Equipment there gets left out; it has to. The sun and dust devastate the paint. It never really rains. Tires are checked and faded in a few months, irrespective of whatever treatment they're given.
The mechanical service components are maintained with zeal, though. All of the fluid changes get logged in a book I keep, as well as online. Hour meter, date, and fluid type (as applicable) are written on filters when they're changed.
Many people have similar circumstances or thoughts as I do, and are simply using their machines in conditions that don't do anything for the cosmetic factors of their machines. Additionally, most of the cheaper compact diesel tractors are 25-35 years old. Look at it this way: when did you last see a good looking 1979 Toyota/Nissan/Datsun pickup truck? Or any other car from that time period? There are some out there, and some people restore them to nice condition. But the guys who bought a work truck in 1983 used it to work, and it will usually show.
I'm not saying to not worry about it, or care. But if you were looking for an early to mid-80s car, what would you expect to find? Especially at the more budget end of the scale?
There also isn't that much difference between an old tractor and a new tractor in terms of what it can do. There are certainly refinements as far as user-friendliness (HST, cup holders, drooped hoods) but in terms of reliable equipment to do basic "tractor stuff" around a small lot, a 30 year old Kubota/Iseki/Yanmar/Mitsubishi/Hinomoto (or their domestic analogues) does everything just fine, and hasn't lost that much in value. As a result, prices for the older stuff tends to stay higher than would be anticipated, since its usefulness hasn't declined.
What are you looking for? Anything specific in mind? We love to help spend other people's money!