Oscar wins with least amount of campaigning [closed]

Studios spent millions on Oscar campaigns to entice academy voters.

These numbers can range from $3 to $10 million:

For films in the thick of the best picture hunt, smaller studios can expect to shell out $3 million for lobbying voters, while major studios figure to spend up to $10 million, sources tell Variety. And even though the meals and parties are ostensibly over, the cost of mailing watermarked screeners of the films to Oscar, guild and (earlier) Globes voters can set studios back up to $300,000.

These budget are used to publicize their movies widely:

Academy members receive For Your Consideration (FYC) booklets, DVDs, copies of screenplays, and CDs of soundtracks; they field invitations to screenings and Q&As; and they are targeted by FYC ads in industry publications, on social media, and, if they live in a place like New York or Los Angeles, ads on billboards, in the subway, and atop cabs. Vox.

So some may believe that the amount of money studios spent on campaigning is in direct relationship with their chances of getting their movie across many platforms as possible and hence increasing their winning possibilities.

My question is, are there any Oscar wins (in the major categories) with the least amount of campaigning for that year?