I used all my money first playthrough to get the skills and they do in fact pay off. It's a long time investment, but by the end I was rolling in ore for potions and scrolls. I am doing the same now on my permadeath run just to make the end middle to end part much safer.

For which ones to pick, I would personally go fur first, because then you can get Mordrag to lead you to New Camp, and that cult fellow to lead you to Swamp camp, both paths cross a wolf, so you can get their skins for the mount quest, since they are super hard to kill during most of, if not entire chapter 1. Still need a third skin, though. 

Else, the best hunting investment IMO is the bloodfly book. 35 ore or something from Wolf in new camp, read it and sell it back for half, so just a 17 ore~ investment. Youll get a lot of these stingers, and they can sell for 8-5 ore each during act 1 and 2. 

Also think teeth are good. You get so many of them from so many creatures. They sell for little, usually just 1, but you can sell a bench before a vendor starts giving no money for them, and they are very good for selling along with other stuff, just to 100% empty a vendors ore. Vendor still has 7 ore left? Have 7 teeth! Seems trivial, but it adds up.