The Prana Revolution mat is listed at 8.2lbs for shipping - which I did not look at until you mentioned it was heavier than the black mat, jlg!
I don't know how but I got the impression it was lighter and easier to handle from the reviews I read. I had better read more carefully.
Samarjit, you are right, it is business now. We really don't need to buy a mat, it just makes it more convenient for us to have one if we feel the need for it I think.
I know I like having the convenience of a mat I can just roll up and take it where I want to go, and I plan to get one that will last me many years and still be environment friendly. For now, I'm using my cheapo thin one I got for $11.