Prohibition is total deregulation. Whether it's alcohol or drugs or prostitution, it not only doesn't work but backfires in spectacular fashion, creating wealthy and ruthless criminal empires. Proponents of prohibition understand that it doesn't work but support it anyway because they don't care about anyone who might chose to do what they disapprove of. They're content with using the consequences of prohibition to justifying prohibition, the sort of circular rational that is typical of people who aren't being honest or reasonable.
No, taxing it too much will have the same effect as prohibition- forcing it back into the black market.
I think it should be completely untaxed.