cassettes are the still the greatest format for heavy music. And they are so very cool, whereas cds are cold and without spirit.
Cassettes are highly collectable. Regarding Opeth, I've got "damnation" and "deliverance". Those are made in Indonesia, because tapes still have a market over there...in this case I really don't know what's the real limit between legal or illegal. Because it's not sponsored by the band? well, who cares! Anyone wants to try to define the thin line ?