Building a techie business case

[MoonWitch]

This doesn't really fall under anything wow-related, but it's "tech" - so I decided this might be most suited. If not - mods... kick me and relocate?

Basically; part of my job entails writing (and maintaining) a bucketload of Powershell scripts. I am not here for the debate on whether or not powershell is good or not. I find it rather convoluted at times. I mean "Get-ADGroup -Filter {Name -like "*view*"}" JUST to get all AD security groups containing "view"? Yeah, I had hoped before I knew better it would be simple; say like "Get-ADGroup *view*"
I digress..

Basically; we currently have multiple versions of the same file with names like "Copy-Groupmembershipv12.ps1", and they all contain a changelog more or less etc. I am a Git user, I see possible benefits in using Git to actually have a version control system going over those scripts. It's just 3 people using them (or rather writing them), but we each change them, save a new version, mail the other 2 to tell them to copy them over to their machine.

I assume by now you're completely face palming and screaming obscenities. Bear in mind; this is NOT my choice. I hate this ridiculously moronic workflow. But I work in the financial sector, and as my luck has it - everyone seems deadly afraid of the cloud. But given or a private repo or running a local git server (which is harder to set up of course), and some rules related to "You still can't store passwords in the scripts themselves" - I do think it would be fine.

My only issue is that I've never actually had to make a proper business case to prove the obvious benefit of using Git (or Mercurial, I don't care actually) for our scripts. How would you address this to your boss?

Basically :
- We would STILL have our own version locally
- We'd keep a perfect log of who changed what and thus could have caused issues.
- We have an easy way to revert to an older version if something went wrong.
- We have a full backup of all scripts
- We will have easy documentation per scripts (in the commit logs)

Cost isn't relevant, I would use BitBucket private repos (I'd rather use Github, but the private repo's have a cost. And cost sells worse than free )