Hey guys. I've been using this method for about a month now..and I have no use for it anymore, so I'll just post it here for everyone. I like to share methods that I discover on my own with people, so expect more guides from me on various things are I find more. I'll share all that I can help you with, but I will only show you methods I discover on my own, not going to give out anyone else's work, so don't even ask.
Read this before you go on any further:
The account you are transferring to MUST have cash on it (At least 500k or so, the more the better)
This only works for about 500k-1M every 4 hours because of GE Limits, but it can be done in a matter of 5-10 minutes.
If done correctly, there is NO gp loss on the account you are transferring from

This can be done in F2P/P2P, however P2P works better as it contains more items.
What you do is this: Log on to both the account you're transferring from, and the account you're transferring to in the same world at the Grand Exchange. If you don't know how to do this, I'll post a mini-guide at the end of this post.
I will refer to the player the money is being transferred FROM as Player A, and the player the money is being transferred TO as Player B.
Here's what you do:
Player A goes to the Grand Exchange, and searches "Corrupt." If in F2P, your results will only display Corrupt Dragon items, however, if you're in P2P, you have a bigger selection of what to choose from.
Player A then buys a Corrupt item from the GE at Minimum Price. Items that usually work for me: Dragon Sq Shield, Vesta's Chainbody, Statius Platelegs, Dragon Spear, Dragon Dagger, Dragon Med, Dragon Plateskirt, Dragon Platelegs. Try to avoid Vesta's Longsword, as I've had a Sell Offer in the GE on Player B for two days now and it hasn't sold.
Player A then trades with Player B and sells these items to Player B for Market Price. I'm not sure of exact prices..but I'd estimate roughly 20k profit for an item worth 300k.
Player B then puts a Sell Offer for the item they bought in the GE for Minimum price.
Continue buying corrupt items on Player A and selling to Player B until either A: You've reached your buying limit for each Corrupt item on the GE, or B: You've run out of cash to Transfer on Player B (Until some of your items in the GE sell).
So, I hope this helps everyone out. Like I said, I've been using it for quite a while now on my pure, and it helps a lot. I'd recommend NOT doing it as a main source of cash though. It's just something I do on top of making cash on my pure to get a few quick 100ks :P. If you need help with how to make money starting out on a pure, check out this guide I made a couple days back:
http://sythe.org/showthread.php?p=5013568#post5013568 (It's kinda sucky, but it gets the job done :P)
So like I said, here's a mini-guide on how to Double Log so that you can use this method.
Have two FireFox, SwiftKit, Internet Explorer, or whatever Browser/Client you're using to play RuneScape open. On both windows, go to the login screen and have the Username/Password typed in the boxes. Go to one screen, then click Log In. QUICKLY hit Alt+Tab to change to the other window, and then click Log In on that account too. If done quick enough, you should log into both accounts at the same time on the same world
I hope this guide helps you guys, I'll read through all replies, so post here and tell me if you like it, if I made any mistakes, or if you have anything you'd like me to add.