I haven't tried this myself,nut from what I've read it is best to use "new" media, at least unused media, and then only as an emergency disk.

I purchase new old stock every now and again to keep variety of unused media available, as well as keeping my old disks stored well.

As to where, well every now again someone here will post that they have spare old disks for sale, and there is always eBay, both for used media,as well as new old stock.