I have a 512GB drive in my MacBook Air M3 with 225GB free. Saving 1GB is 0.5% of my total free space, and it is definitely "below my line." It is a neat tool still in concept.

When I ran it on my home folder with 165GB of data it only found 1.3GB of savings. This isn't that significant to me and it isn't really worth paying for.

BTW I highly recommend the free "disk-inventory-x" utility for MacOS space management.