Got milk?

Why is it that milk costs more per litre than petrol? In my understanding it’s completely renewable. It’s not like we’re approaching “peak milk”, with ever dwindling supplies to satiate our growing thirst for our rampant consumer driven lifestyles… It’s a travesty I say.
And something must be done. There’s your cause of inflation right there – especially with fuel prices back down around the $1.10 per litre mark.