Do some research, find out which herb is used most in herblore around the levels of 60-96, then invest in that herb, ranarr might be pretty good as prayer pots are commonly made.
Haha, thanks TJ. and ya onepartyhat, its overhype for a tiny bit more xp but if your doing skills like herblore, it pays off. Switched my investment to clean snapdragons, buy em out =P
Someone donate some clean or grimy avantoe to me :'( I bought herb supplies a few days ago but can't afford the avantoe to add to the super attacks I'm making.