Hmm. I know Django admin is one of the best things about Django... but why $1m? If each developer gets paid $200k/yr, that's 5 developers for 1 year? Sounds crazy to me.
More importantly, it's been continuously evolving for nearly 20 years at this point.
Anyone who's actually tried to do a from-scratch rewrite of a system that has 20 years of development behind it will know that 5 engineers for a year is probably optimistic!
Given the flexibility and depth of the django admin, 5 good developers working on it for 1 year sounds about right.
200k/year might sound like a lot but then in a real business there are various overhead costs as well.
I'd say $1m is probably on the lower side of the estimate. Factoring in project delays and misc Murphy law things, wouldn't be surprised if a mediocre team underdelivers with a crappy immitation of the django admin interface after blowing through a couple mil.
There is the frontend and the backend, the whole introspection stack, the admin customization layer, and the integration with permission, filtering, caching, etc.
Add on top of that documentation, testing, and making the whole thing completely independent and pluggable (as django must work without it) but perfectly integrated with it (settings, forms, template overrides, etc).
That's a lot.
You might get feature parity with less, but not with the same guarantees of stability and maturity.
The admin has a a LOT of features.
More importantly, it's been continuously evolving for nearly 20 years at this point.
Anyone who's actually tried to do a from-scratch rewrite of a system that has 20 years of development behind it will know that 5 engineers for a year is probably optimistic!