Bought this guide and just like to say..
The first method is obvious, the only new thing I learnt about this guide, for the first method is how to obtain the ingredient that is EXTREMELY hard to obtain.. and you'll need member. Because if you're F2P, it's extremely hard to get the ingredient, so you might as well be a member.
And yes, you're obtaining the ingredient while doing it. (As a member)
Second one involves GE, buy low and sell high. Like Anthony said, it's different, because you can sell it immediately after buying. It works, but it doesn't make 4m/h for me, it makes 2m/h, it's still a lot of money though.
This one isn't well known IMO. First one is though...
What I learnt from this guide :
- Power flipping
- Obtaining the ingredient and doing the method at the same time

(There's a video in the guide, a link to the video)
Still pretty satisfied, but it's not 4m/h, it's half of that which is 2m/h.