There are much easier and profitable drugs to sell than weed. If you're going to break the law anyway, go for something with a bigger ROI. Granted, dealing with tweakers is less enjoyable than stoners, and more dangerous, but hey them big dollars come at a cost. You also have to be prepared to turn away about 30% of your business because they are trying to trade you some 30 year old stereo, or other useless garbage like a fucking blender... I'm not speaking from experience of course. But I've read stories about it on the internets.