I think the main costs are alle the necessary new licenses, mainly KSS 8.6 and Kuka Windows Embedded, you need to buy from KUKA and this is something that can not be avoided. Everything else would be software piracy and therfore illegal. If you can upgrade to 8.6 (which is running on windows side a Windows 10 version) depends on the mainboard version (MCC 20, 30 , ...) you have. I think these dependencies have been posted some time ago in this forum but I did not search for it now. But as always asking KUKA would probably also reveal this.