I'm renting an apartment with a broken oven. I bought a used electric tabletop oven from the thrift store for US$17, several times larger than a toaster oven, with bimetallic thermostat and mechanical timer. I live in Argentina, but my memory is that rich-country thrift stores and garage sales have even lower prices, because there are less poor people competing to buy their wares. When my mother moved to Japan, she furnished her whole house from the sodai-gomi. For free.

My experience with poverty is that the main obstacles to things like cooking isn't lack of resources like ovens exactly. Rather, it's more like lack of autonomy; maybe someone will take your oven away because they are afraid you'll set the building on fire, or because they want it, or a combination. Or you're just mired in learned helplessness to the point it doesn't occur to you. Or you're not functional enough mentally to keep the oven clean enough to use. Or the police sweep your camp and your oven goes in the dumpster along with your birth certificate. Or maybe you can get the oven but your work shifts lack the predictability to be able to plan meals ahead of time.

But it's almost never because you can't come up with the US$17.