I just reached 85 Dungeoneering earlier and wanted to give Frost Dragons a try. But looking at a few guides, it looks like I'll need Soul Split to be any good there.

Would I still be able to make decent money there without soul split? Apparently 4m an hour is with all the best stuff, so good to me would be like 1.5-2.5m an hour

 

I'll be using a zamorakian spear, normal extreme potions and a pack yak

Or would it be worth spending 50m on Soul Split if I could potentially not enjoy Frost Dragons?

Ranged is almost as effective as melee(particularly because you have a spear) if done right so i'd say that would be the best way to go. Getting soul split is, as i see it, always worthwhile as it'll always be useful, particularly for the great moneymakers. If you want to melee without soul split you'd have to use sidestepping techniques in order to avoid damage when on lower hp.

Ok thanks

I'll see how well it goes with ranged, if it goes well I'll put the money towards overloads and soul split

 

If I do, which one of those should I get first? Herblore would be roughly around the same price as prayer if I got it to 92

Overloads are only really necessary for the highest level boss hunting, borderline useful if you can already slay frost dragons(as it's the same profit anyway), but soul split, and particularly turmoil will be extremely useful for any meleeing you are looking to do.

Thanks :D