The Australia Film Commission has a set of feature articles worth perusing. One in particular is called “The Financial Lowdown“.
Though this article is a tad old (it references films shot between 2000 and 2003), the content is still excellent. There’s a breakdown of a $1M production budget that helps with understanding of generally where in the budget the money goes. There is also discussion of how many shoot days are typical for low budget features and much more.
So… read it, learn from it, bookmark it! Then you can peruse their other articles too. Are any of them of significant interest to you?
Cheers & happy budgeting to you,