Well, I understand you want this information, but you need to understand the difference between a group buy and a sales thread.
Here, SK is not making any money, he is simply supplying a product at a discounted price to multiple people at once. Its assumed that people that get involved in group buys know what they are buying and therefore just find it at a better price being in a group (economies of scale purchasing).
On the other hand, in a sales thread, the sales person is trying to sell the product. Therefore he needs to know all the information about the product etc to actually sell it to the customer.
As above, call GCG or have a look on their website www.gcg.com.au. Specifically, here http://www.gcg.com.au/Catalogue_Menus/Upgr...pgrade_gtst.htm