Even adding in compliance, audit trails and security hardening, this is not an $86M project.

Maybe not $86M

But I can easily see it ranging into the 10s of millions of $$ (even Aussie dollars).

Add-in multiple devs, project management, audit compliance, security compliance, documentation, etc … this is easily a $20m+ project

Just because you can do something in a few dozen lines of code (which actually call thousands-to-millions of lines of libraries) doesn’t mean you’re “done” — you need to validate every library, fork (and document the ever-living crap out of) specific versions of libs, etc.