Show "Ask for shipment cost" in cart

[woodhouse]

Hi there,
I'm using VirtueMart 3.4.2 and Joomla! 3.9.1,
Due to too variable shipping costs fot the item I sell, I need to calculate the shipping cost for each item for user living in certain countries and I know it's not possible.
To solve the problem I would like to show something like "Ask for shipment cost" in the cart, to allow me to set the correct shipping cost in the order.
Now I configured a very high shipment cost and I show a message asking to write me before to pay, but that's only a work around.
Is there a plugin or module or any other method to do this?
I made a long search, but I did not find any.
Thank everybody for help.

[jenkinhill]

You could use a purchase order system, so they don't pay in the cart, but you get the order email and can subsequently invoice the customer once you know the shipping cost.  Google purchase order

[GJC Web Design]

or use the vm std payment plugin and the std weight plugin with zero costs, filtered by countries and appropriate labels and messages

[woodhouse]

Thank you, maybe I find the solution.
Using the hint by jenkinhill I found this topic https://forum.virtuemart.net/index.php?topic=127023.0 that gave me what I hope is the solution.

Thanks everybody.
Daniele