With a budget of $1.5 million, which film was the cheapest produced to win an Oscar?

Moonlight is the cheapest film to win a best picture Oscar at a 1.5 million dollar budget. I couldn't find ANY oscar, though I imagine there were some made more cheaply.

https://www.cbr.com/great-low-budget-films-won-oscar/

I found an Oscar winning film with a lower budget "A Seperation." With an $800,000 budget it is an Iranian film from 2011. Although not best picture, it was the best foreign language film. I would guess that would be the full length film category most likely to have a lower budget, if there is one. The best live action short film would likely also have low budgets just based on run time.

https://en.wikipedia.org/wiki/A_Separation

The Broadway Melody, also known as The Broadway Melody of 1929, is a 1929 American pre-Code musical film and the first sound film to win an Academy Award for Best Picture.

It's budget was $370,000
https://en.wikipedia.org/wiki/The_Broadway_Melody