How to change the COM_VIRTUEMART_PRODUCT_SALESPRICE depending on products

[Geppux]

Hi everybody. I use VM 3.2.4 and Joomla 3.8.1
In order to have a partire da (starting from) instead of Prezzo (Price) in the category page (here is an example https://www.mulligan.it/it/sacche-da-golf.html) I made an override of the language and than I modified the file template/nametemplate/html/com_virtuemart/category/default.php to use the costant COM_VIRTUEMART_PRODUCT_UNITPRICE that I don't use (seen that the costant COM_VIRTUEMART_PRODUCT_SALESPRICE was already overrided with a different value that I need). Now all the products has "a partire da" but is it possible to have "a partire da" (the costant COM_VIRTUEMART_PRODUCT_UNITPRICE) only in those products that have childs products with higher prices and leave the COM_VIRTUEMART_PRODUCT_SALESPRICE costant in those products that don't have differences in price but only one price?
I hope I was clear in my explanation  thank you.
Giuseppe.