No, shorting bags is for shitty dealers.
Thats not how you make profit, thats how you make enemies.
To make profit, it's simple. You buy in large quantities, which means you get a cheaper overall price, and then call your weed the shizznizzle bam snap snap and sell it in small quantities. Eventually, if you want to further your game, you make friends with a male hairdresser, and finally a small mexican family who's sole crop is marijuana. It was perfect.