He called to say he has recently compiled a 2 DVD set

Are these stamped DVDs or just burned ones? Anyone can download and burn
their own DVDs these days. But burned DVDs are proving notoriously
unreliable. Stamped DVDs (like CDs) are far more reliable. If he's just
selling free data onto burned DVDs it's hardly worth paying anything for
them. Just download and burn 'em yourself.