I got this snippet from WooCommerce where I can now add my own price string for each composite product in back-end.
I have added, as I wanted to have it: "From: € 887 incl. tax". This shall be fixed, no link to the database but the style needs to sync with the UX Flatsome theme I'm using where "From:" shall be light gray, "€ 887" no changes and "incl. tax" smaller but black and normal style, only smaller than "€ 887". The solution will then help me to let this fixed "text" to look just like the theme does with its "From: € xxx incl. tax" that normally appears.
Thanks for your understanding and consideration.