Buying 20 Mil RSGP you must have method.

Hey traders. I'm looking to buy 20mil from the cheapest seller. My budget says $70.00 but the money will go to the lowest bidder, as I'd prefer to pay less than that. I DO NOT have my own method, so before you post you better have a good method for this trade. I don't want it to take more than a day or 2. Please also include in your posts how much money I would be required to have on my account to start with in order for the xfer method to work. Thanks for looking and happy bidding!