My buddy is going to this, I thought he was joking. I mean...Oaksterdam? What a fucking marketing ploy.
Anyone with the desire to attain any of the knowledge they teach there could do it for free, perhaps the social atmosphere of a bunch of potheads is the allure....
The only benefit I could think of is the 'business' and 'legal' if you wanted to open a pharmacy, but as someone else pointed out, Oaksterdam isn't accredited by any governing body.It's entirely possible to start your own pharmacy/business, if that's what you really want to do, without wasting your money.
If you wanna grow something, you put the seed in the soil, water it, and tada.

Yes, you can get deep into tweeking nature, encourage fruit production, soil studies, feeding, etc. But n a natural, wild environment, cannabis is a hardy plant that can grow with no care at all.