My info from last year is they don't sell stuff to mates. I tried it last year.
Get there before it opens, wait at the gate and if you know what you are after, go in (you can run if you are as desperate as some of the other desperados) , find it straight away and buy it.
There will be a crowd there, and most people are after big ticket items such as tents, winches, bull bars.
Some of the other stuff goes slower and if you are after suspension or vehicle specific stuff etc, it would be good to know part numbers as you may need to go through a big pile of stuff in boxes.