Show the number and size of the single & duplicate source files

[zainalara]

I suspect that most people want to know "When I have eliminated all duplicates, what size am I left with? Will it all fit on drive x?"

Currently, my scan result tells me:
Total size of all files: 21 TB
Files have duplicates: 16.1 TB

So 21 - 16.1 = 5.9 TB of unique single files that I can't delete.
But for the duplicates, :
I might have two 8 TB files, so after de-dupe I will be left with 5.9 + 8 TB = 13.9 TB
or might be four 2 TB files, so after de-dupe I will be left with 5.9 + 2TB = 7.9 TB (So, yay! It can all fit on my 8TB drive!)

(In reality, my dupes are 8 million files, but I simplify here.)