Eh.... probably sold as blank. Who knows what's actually on them, anymore? Years of downloads and test disks, work disks, backups, etc... Really, what can you do with an old collection that large? Sell them in bulk, or, my choice, let them age in the closet.
Who knows how many of them ever worked, or were just bad cracks, or whatever, to begin with. Let alone how many have deteriorated with age. ;-) Might be a fun treasure hunt for someone with enough free time, though.
I've opted to let my set of thousands of old DS/DD disks age in my closet. My fiancee's little brother likes to pick through the stacks now and then. But other than that, they just age, cuz I'm too lazy to sort them, and I can't bring myself to scrap them or sell them in bulk.
