They are just generic eBay cables with a little price markup for peace of mind that ensures they work.
The diagnostic software is available all over for free. They are not selling genuine licenses or anything, just charging you for the distribution.
My advice would be to use Bimmergeeks. The cables they supply are much better than any generic DCAN cable on the market and they give the software downloads for free here: https://www.bimmergeeks.net/downloads