Thanks to Pro-KB, I worked out that 80 farming will take me about 38 days, and cost me 9.3m or so. That's a lot, but then I can leave farming for ages.
So with the cash from 99 fish, I am going to get 80/99 crafting, 80 construction and 80 farming. If I do say so myself, that's some pretty sweet stats!
PS: Pro-KB aka I Can Pray I is ftw. Really friendly, and I swear to god he knows everything.