This is it in a nutshell, left trying to sell a bag of sh!te we'd never normally touch with a barge pole and 9/10 we have to give to much for them to begin with! Then in my experience if you buy an absolute lemon you'll have to live with it as BCA and the vendor were oblivious to the glaring faults.
"how can people bid on 10 year old plus cars with no appraisal? " if you get very close to your screen and study hard on the "beauty shots" (BCA's own term for photo) you'll be able to notice all the bad paint, scratches and damages and bid accordingly. Then you just need to use your powers visualisation to get an idea of how it's going to smell,sound and run when it arrives