I have a client who uses a standard size box to ship themed items. They want to sell 2 types of box. Pre-Built theme and custom fill. The pre-built themed box would be priced as per box. The custom fill boxes will allow the shopper to add items to the box until it's full. Each item will have a different price and can be different sizes. So if the box has a fill value of 10, I'll need to assign each item a value that will slowly add up to to 10 in order to build the box. Is there a way to do this in VirtueMart?
Any thoughts on this at all?
Have you check for product builder here : https://breakdesigns.net/extensions/joomla/product-builder
It's complicate to use, but perhaps can work for you case.
Else you can develop your own plugin to do what you need, it's certainly to specific to find an existing customfield plugin