About how much of taxpayers money is spent on the war on drugs?

I smoke a lot of weed, and i am really not that educated in how it is doing on its path to legalization in the United States. But i think a really good reason it should become legal is because it would help the economy. I just hate how the government spends tax payers money on the war on drugs, while they could just sell weed and make a lot of money. The question is more out of curiosity than anything else.