I received the Minolta MC W.ROKKOR-SI 28mm f/2.5 lens today. It's in pretty good condition except for some fungus on an interior element, This despite the eBay seller stating that it is a "Clean used lens with no fungus."
The lens is in otherwise excellent condition and my plan is to take it to Camera Works to see about having it cleaned. These lenses are very inexpensive and even if cleaning cost the same as the lens it would be worth it. There are, however, many situations where the particular element can not be cleaned and then the lens is useless. Minolta MC lenses are generally cleanable but not easily.
Here are some shots with the lens from today with some illustrations of the fungus. You can read more about lens fungus at https://high5cameras.com/all-articles/repair/what-is-lens-fungus-the-reason-why/.