The Swiss Air excess baggage information can be found here:
http://www.swiss.com/web/EN/services...s_baggage.aspx
They charged me for being over the total weight limit of 20kg. Some of their flights are 'by piece' and others 'by weight'. European flights are by weight. So I was over 20kg, and was charged per kg according to the rates that are posted on their site.
So, they are straight forward about the fees, but I think the fees are, as you said, crazy.