I think this analysis is a little flawed. I can understand their argument against factoring in opportunity cost as this will vary widely from person-to-person (and is pretty easy to consider on your own), but they also don't factor in waste or cost of the tools necessary to prepare food.<p>For example, the article mentions that they used the cost for only 1/2 of an onion if the recipe called for only 1/2 an onion, but what happens to the other 1/2? Depending on how often you cook at home, how often you go out of your way to use existing ingredients, and how much time you spend meal-planning, you'll either manage to use the rest of the onion (which is pretty easy for something as common as onions), or it will go to waste. Personally, since I'm typically just cooking for 1, most of these end up going to waste unless I want to be eating the same thing for several days in a row.<p>This analysis would be more useful and interesting if it came with multiple "waste factors" for the remaining ingredients, from "completely used" (which is what this article assumes) to "completely wasted". It'd also be more useful if it factored in the amortized cost of maintaining a kitchen that's stocked well-enough with tools and spices to regularly prepare a variety of recipes.<p>For me personally, the difference in cost is much closer than this article. I will typically use all of the "main" ingredient, but additional (yet expensive) ingredients, such as spices, cheeses, etc. often go bad before I have a chance to use them again. I've also spent a significant amount of money acquiring the kitchenware required to cook at home. I typically don't eat extravagantly when I eat out; most meals are ~$15-$17 (incl. tax and tip). For some meals, I buy pre-made food at the grocery store (e.g. salads, wraps) that also come MUCH closer, if not cheaper, than preparing it at home would cost me if waste is included. Some of these can be very close to restaurant quality.