Vending machines cost a lot of metal, but do not take up much electricity. They dispense treats (like crisps/chips, chocolate bars, fizzy drinks, etc). However, the supplies for them need to be supplied from trading vessels. The supplies come in the form of 'junk food'.
These increase colonist's happiness and may even cancel the negative effect from nutrient dispensers.
I like the idea, but i would rather have implemented something before this. What i am trying to say, is that this vendingmachine would act like the final "tier" in food processing, but in real life, one can't live on vending- food. Already, Tynan are planing to improve/ give meaning to the "cooking" skill, so i think some real kitchening kit should be prioritized.
But in the end: it is something that i could have seen in rimworld :)