I know a guy who got his whole house built paying laborers with weed back in the 90's. Had guys lined up to work. The problem Gooberment has with it is it is money grown from the ground and it can't be taxed.
That being said the value of weed is far less now than it has ever been (adjusted for inflation) since this legalization crap they pulled. Nevada's retarded laws on it are so stupid even they aren't making any real money and they are basically the local dealers. What used to go for $4800 per pound 15 years ago is now below $1000.
I can get 1/2 ounces for about $60 now which is 90's bulk prices. They were $150 just a few years ago. An 1/8th would go for $70 back then.