The demand increased significantly with update to 1.9 and will settle higher that it was before. It's between 3r and 5r per block, I guess it will settle around 4r per block.
http://www.azoundria.com/emc/market/index.php?term=Packed Ice&find=Buy/Sell Seems the average is 5r per. May I ask why this is? I was not aware of any changes.
Boats can sail on ice very fast, so building of ice tracks for racing and for travel is a new use for packed ice.