a Magician should not reveal his secrets to anyone. Except other MAGICIANs.
You're quite right Mark.
However, the important word there is 'his' (and this also assumes 'hers' if anyone questions it) so I could quite legally and cheerfully reveal my secrets but not anyone else's. And that's the point - you're asking for someone else's secrets which we can't, and won't, give out because they are not our property. If the originator chooses to sell their secrets then that's up to them and it's also up to you to decide if you want to pay for such secrets.