Yep. Some are just going to be single use black frisbees. You get some that are like pristine and then some that are far too scratched up to listen to. As long as you are buying used lots, as opposed to paying market price for the selective used records already culled, you will run into duds.
I still do it though, because you never know when you hit a mother load. Especially if you love classical music, there are still some bargains to be had. Not so much on Jazz and Rock 'n' Roll "collections" -- they are usually overplayed and scratched up.