You cant grow (enough) tobacco in your backyard. You can buy an entire plug and play system on Amazon and grow a LOT of weed.
Weed is one thing that doesnt scale up particularly well. To get the best price point, you have to have the best product. The bigger your operation, it becomes exponentially more difficult to grow fire. You can grow good or really good on a large scale, but certainly not the best. Cannabis enthusiasts will always pay a premium for the best stuff.