Worth keeping the 4/5 wargod on my new born spirit mage?
Or is it worth gambling even more gems to get revit/berserk?
You have to ask yourself how much you are willing to spend.
You could get the best talents and spend almost nothing or sell all of your worldy possessions and still not get them. The real question is does the talent mean that much to you?
You've not got the worst talent by far for a SM so I'd say only spend if you have and are willing to spend the money. Be sensible and remember it's just a game.