Haha, check out this:

http://www.ksrevenue.org/perstaxtypesdrug.htm

Drug Tax Stamp

The fact that dealing marijuana and controlled substances is illegal does not exempt it from taxation. Therefore drug dealers are required by law to purchase drug tax stamps.
The drug tax is due as soon as the dealer takes possession of the marijuana or controlled substance. Payment of the drug tax will purchase the drug tax stamps. Attach the stamp to the marijuana and/or controlled substance immediately after receiving the substance. The stamps are valid for 3 months. Drugs seized without stamps or having expired stamps may result in criminal or civil penalties which may include fines, seizure of property or liens against real estate.

A dealer is not required to give his/her name or address when purchasing stamps and the Department is prohibited from sharing any information relating to the purchase of drug tax stamps with law enforcement or anyone else.

Purchasing drug tax stamps does not make possession of drugs legal.