Can I run more then 1 instance of scrapebox without buying another liscense?

Yes. You can run multiple instances of scrapebox with one license, however all instances must be run from the same physical machine/operating system.

Each instance must be run from a separate folder.

For instance create a second empty folder:

/scrapebox/
/scrapebox2/

Then copy the contents from your original scrapebox folder to the second folder so you have two separate copies.