This is simple. You put the materials in the trade window. You put the price you want for each in the window. The Trade Window multiplies and gives your requested amount. The buyer puts their amount in the window.
You can also do the same for weapons and other things. Put that UNID Req 8 Chaos axe in the window with a price of 30k. This will help in international trading.
This will solve a few problems associated with lazy people who don't own a calculator.
