Yes, that's all true but I don't quite see what you're disagreeing with. I agree that it definitely is cheaper for restaurants to cook large numbers of the sam

Yes, that's all true but I don't quite see what you're disagreeing with. I agree that it definitely is cheaper for restaurants to cook large numbers of the same meal, and they have many other expenditures which raise the price of your meal. But for a single meal, the question is whether you can cook it for less than the price at an equivalent restaurant. In many cases, this isn't the case unless you're cooking in large quantities and eating the same meal for several sittings. Yes, using seasonal ingredients is a good idea -- but a lot of restaurants also do that, and their groceries are still much cheaper than yours anyway. For example (in Australia), if you want to make just one portion of Thai curry you need at least $60 worth of ingredients (your protein, chillies, lemongrass, galangal, palm sugar, shrimp paste, fish sauce, peanut oil, coriander, coconut milk, Thai basil, kaffir lime leaves, limes, lychees if that's your thing, and so on). So if you're only making one meal it's seriously not worth it (you can buy a decent Thai curry for a fraction of that price). But if you make 10-12 portions of curry (or you make a large batch of curry paste and use it for different dishes) then it starts to become cheaper per-portion.