At that discount, it would probably be damaged beyond repair or a scam. I am incredibly poor myself so I will just stick with my inherited gear and FOSS software.
Read what happened to me yesterday
Right after I read this post I went to take photos of a local abbey. When the blue hour was nearly over and so was my shoot, I was heading back home. On the way I noticed a photographer prepping his equipment on the burm behind my spot. Probably getting ready to shoot Moon, I thought, as the beautiful sky became clear at that time. Boldly I climbed and put myself right next to the guy on the burm. A telephoto lens was needed so I pulled out my mass-production Sony 55-210 which I bought used for about $150. The guy looked at me, smiled and pulled giant Canon FE 600mm f4 out of his bag. Not only I was impressed by its size, having looked at your references, I knew its price tag is $11,000. Never I felt so much of a pauper
I often check dealer used stock when I want something. Photography is an area where people often keep buying better or just changing for some reason or the other when there is nothing wrong with what they had so there are loads of lenses and flashguns out there that have probably hardly been used. Camera bodies too but it not a bad idea to see if actual shutter counts can be obtained from them. It seems that isn’t as simple as people think on Canon.