AFAIK, we do not have anything like asset seizure in Germany. And the prison system over here is much less privatized / industrialized, so is not exactly a profit center.

A well-staffed, well-trained law enforcement apparatus is fairly expensive, too.

And consider that without proper treatment, widespread drug use incurs costs that do not show up on government budgets as such. Drug-related crime (theft, burglaries, etc.) comes to mind.