Get a German Shepard and train it to find drugs. Get a job as a police officer, but take your dog with you on patrol. Keep all the drugs you find, and hope you luck out and bust someone hauling 120 pounds of cocaine or something crazy like that.
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Grow 1,000 pounds and sell it
If you were doing 20 pounds a harvest, every two months, that's 120 pounds a year. Grow for a little over eight years and you'll have it.
Or do a couple small grows, than some ridiculously large one-time grow -- like, rent a commercial warehouse and truck in 4,000 plants and just hope to have them flowered and harvested before the warrant gets issued.
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Find a young girl, or your daughter / stepdaughter, and manipulate her into selling her virginity at the Bunny ranch and giving you the money. If you are the right mix of charismatic and sociopathic, pretty much any plan that involves manipulating rich people has merits -- getting a million quick is a hell of a lot easier if you are around people who have millions. Hell, you could probably get some fat heiress drunk and just not pull out -- get a family, money and laid all at once.