How much exp an hour is it if you craft FIRE runes using the dueling ring method?

Anything upto 25k an hour i think.

Can anyone else cofirm these numbers?

25k an hour seems a bit high.. I'd go with 20k.

It depends whether you have super energy restores to keep up your run energy. Ideally you'll have sufficient herblore level to make your own, then you can hit the top end of rc xp/hr without spending any money, you'll just have to spend some time in advance preparing your pots. If you are going for a big gain in xp, and frankly its pointless if you're not, then the time spent making the pots will pay off. At least, that is what I found, speaking from personal experience.