Some people asking why there should be additional fee for MacOS version. Is it fair?
Right now we have ~900 $10-contributors.
10 of which complains about "cheating"

Let's assume that half of $26-and $100-contributors also have Macs.
This gives us 10-1+9+7 + 169/2= 110 Mac OS users vs. 967 non-Mac OS users.
SVP 4 for Windows is a rewritten Manager.
SVP 4 for Mac is a rewritten core libraries plus some OS-dependent part of the new Manager plus a lot of headache (beginning from I don't have Mac).