If a lens is outdated and cheap, then it's probably
- broken
- very old
- with fungus inside
- damaged and the damage is hidden (decentered, automatic diaphragm doesn't work properly anymore)
- with a mount not fitting to any current camera body
- part of a heritage when the heir doesn't know about the value
- difficult to focus manually with a modern DSLR, less difficult with mirrorless
- difficult to get spareparts, if you forehand manage to find a repairer. (See Toni-A's cable problem)
Everything is just good for the adventurous types saving tons of money in getting a collection of lenses nobody has because nobody wants them [/irony]. In that case, "outdated" to me really meant a thing you need to tear apart bit by bit and clean and eventually fix it and put it back together. The other lenses like the Mark I types when there's a Mark II still have their prices and cost a bit more than a song. Probably there are some outdated lenses around which still are a jewel (and their owners mostly know about), but the cheap majority is mass production. I don't want to get a Revuenon, old Sigma, old Tokina, battered Vivitar and what their names were, they were third best choice at their time and today 5 € is too much for them to pay.
