The reason on the first additional postage was "Unfortunately DHL have added a temporary Covid Surcharge on all orders to Australia and New Zealand"
This time "due to the size/shape and/or weight we are unable to send your order to you at the original online quoted price." But shouldn't they know the size and weight on the product they selling. The original quoted postage was £108, it is now £150. That is a big jump.
Its not quite that simple unfortunately. Its down to volumetric weight and how precisely we can pack various items together (all shapes and sizes). Its not a case of we don't know the weight and the size of the goods.
Take a Mini front wing for example. They weigh around 2.5 Kgs each. Most people order 2, which brings it out at 5kgs for the pair. (not as much of an issue for UK based orders)
Volumetric weight of one wing is 25Kgs. If we used simple logic, anyone ordering 2 wings would be charged at 50Kgs. But in reality they can be packed in the same box, so the dimensional weight would still be 25Kgs. If we were to quote the pricing at 50Kgs the price would be horrendous, and no one would order them.
I've tried to use the simplest explanation I can, if you need any more information please let me know.