I’ve checked the pro license price , its 7.5 for 10 websites , well for low 3rd world countries it is expensive i am not sure if there will be later a license for 1 website or 3 websites for less price as i have only 1 website running VM min and i believe there is a lot of people who is using VM like me .
sorry for my english, i hope u got the point. ( keep price but make it for 1 website or 3 ws license )
Main difference are some scripts , user friendly things and support from Virtualmin against the free GPL option.
You can if you don’t need those install , scripts and support use the free GPL and Support VM with a “gift” sponsor / donation.
Please know that only making invoices bookkeeping and banking cost money to, so to low price per month then nothing or to little left i think.
Also support for if you have one website or 10 is almost the same work for Virtualmin Support!
I understand you, using myself a free option to to learn, test, and low level less important sites , in exchange i try to put some of my time here on userforum.