Isn't there a possibility to just improve the shipping costs section of Virtuemart itself?
The problem now with this option is; that it doesn't use the weight of the product, it uses the total weight in the cart.
So basically it shows the shipping costs of the items which are in your basket on every product page.
I have myself multiple shipping options based on price; standard, signed for, insured.
The strangest thing is that the price of an item does trigger another shipping option.
So with a more expensive item, the VM shipping shows insured shipping with its price.
However the weight is always "zero" with an empty cart, so even if the product weighs 30 kg, it will use 0 kg as calculating method.
I have tested it with people abroad, and the correct shipping for their country is shown, although it is the lowest weight class shipping.
If the weight of the product is also used with the shipping calculation at the product page, it would be much better.