how do you get things so cheap?? Looking at things in the big picture.

I have recently been asked by guild members how do you get things so cheap... Well this is due to alot of economy issues that you have to take into account.  There are alot of ways that I can obtain things cheap for one I buy a bulk amount of things from people who want to offload really fast. Recently I connected with a person who wanted to give me a shipment of 200 stacks of ore ( 12kg). Now the market price at the time was over 4g so I went and got them for 3g each saving me over 4,000 gold like that. Now additionally I had the opportunity to post 10 stacks of these to the AH later at a premium price.  Selling stacks for 4.5g each or 90g per stack.  minus the ah cut  4g50s and 2g40s per stack  giving a price of  83g10s  4.15.5 each 831g total for 10 stacks giving a new amount of 190 stacks for a new price of 2g93s91c each this is only with 10 stacks tho you have to understand. Now by selling 100 more stacks at 80g a stack minus the ah cut of 6g9s (73.1g) for a new amount of 90 stacks costing 3858g.59s or 2g14s each.  So by selling all of these others off I have basicly gotten my prices down to less then half the market prices.