I wonder if it would be helpful to have a brief FAQ for the Trading/Swapping side of things just listing the weight of 1, 2, 3 disc combinations and listing the average postage costs for sending them. It could have prices for US to US; US to Canada; US to Europe and vice versa, and then save members who have stamps at home from having to find the time to get to a Post Office and weigh everything.
Just a thought.