I understand why that sounds like it should be true, but I'm not convinced that it actually works out; I can get an esp32-cam for <$10 with no effort off the shelf, so if the cost to build the thing in is even vaguely close to that then the real cost is going to be dominated by the internet connectivity and phone client side of the equation. I guess it depends how much food we're talking about throwing out and how much it costs, but that strikes me as plausibly within an order of magnitude.