What is the cheapest and the fastest way of getting 89 Herblore?

 

I have like 100M to work with and I think that should be enough..

I've always personally been the kind of person that gets their own items, I farm all of the herbs I use, or get them as drops from monsters, which makes herblore for me profitable :P

 

I have heard that making Prayer Potions are pretty cheap...as far as herblore costs go.

Cheapest: Identifying Torstols

Fastest: Buying the highest level (unf) potion you can make.

 

What I'd actually recommend is buying Snapdragon potions and making super restores until 76 herblore, where you should buy Lantadyme potions and make Magic potions. At 84 you should make Recover Specials, and at 88 you should make Extreme Attacks.

 

Beware: Prices change and you should watch them.

 

Here's the rule of thumb: if you consider making (unf) potions one of your better methods of making cash, you should buy herbs and make the (unf). If you consider making (unf) potions a bad way of making cash, buy the (unf) pots yourself. Knowing you Donkey I know that this is a bad money maker for you, so definitely buy the (unf) potions.

http://runescape.wikia.com/wiki/Calculators/Unfinished_potions