Lets see. Here's a few of the bigger parcels I've had forwarded (please note measurements are in American so use google or something to put them into metric so you can understand them)
Dimensions: 15.00″ x 20.00″ x 11.00″
Weight: 7.6 lb
Cost: US$78.75
Dimensions: 11.60″ x 20.00″ x 10.40″
Weight: 4.1 lb
Cost: US$39.65
Dimensions: 16.00″ x 18.00″ x 11.00″
Weight: 5.1 lb
Cost: US$48.56
Each of those items was going to cost nearly double if I had of sent them direct to me rather then with the forwarder, but in most cases that's because of scummy sellers trying to rip off non-yankee doodle dandees
You can also use their postage calculator to get some rough ideas of what options are available: http://calculator.shipito.com