Not everything will be cheaper to make from scratch but the quality will be better. With the bread, a decent homemade loaf will be far nicer and will fill you up much more than the cheapest loaf from the supermarket.
I have a cake in the oven at the moment, and to buy the same cane would probably be cheaper than the ingredients I used(although I already had them in) but I know exactly what is in it( ingredients) compared to the huge list below of what is in a supermarket version.
ngredients
Chocolate Flavour Buttercream (21%) [Sugar, Unsalted Butter (Milk), Glucose Syrup, Water, Fat-Reduced Cocoa Powder, Dried Glucose Syrup, Cornflour, Preservative (Potassium Sorbate), Emulsifiers (Mono- and Diglycerides of Fatty Acids, Polyglycerol Esters of Fatty Acids)], Sugar, Milk Chocolate (11%) [Sugar, Cocoa Butter, Cocoa Mass, Skimmed Milk Powder, Whey Powder (Milk), Anhydrous Milk Fat, Palm Oil, Emulsifiers (Soya Lecithins), Sal Oil, Mango Kernel Oil, Shea Oil], Belgian Milk Chocolate (9%) [Sugar, Whole Milk Powder, Cocoa Butter, Cocoa Mass, Whey Powder (Milk), Emulsifiers (Soya Lecithins), Flavouring], Fortified Wheat Flour [Wheat Flour, Calcium Carbonate, Iron, Niacin (B3), Thiamin (B1)], Pasteurised Free Range Whole Egg, Glucose Syrup, Unsalted Butter (Milk), Whipping Cream (Milk), Fat-Reduced Cocoa Powder, Belgian Milk Chocolate Curls [Sugar, Cocoa Butter, Whole Milk Powder, Cocoa Mass, Whey Powder (Milk), Lactose (Milk), Emulsifiers (Soya Lecithins), Vanilla Extract], Water, Palm Oil, Dried Glucose Syrup, Humectant (Glycerol), Palm Kernel Oil, Pasteurised Free Range Egg White, Soya Flour, Invert Sugar Syrup, Rapeseed Oil, Skimmed Milk Powder, Palm Stearin, Raising Agents (Diphosphates, Sodium Carbonates), Grape Juice from Concentrate, Rice Starch, Emulsifiers (Mono- and Diglycerides of Fatty Acids, Polyglycerol Esters of Fatty Acids), Preservatives (Potassium Sorbate, Acetic Acid), Cornflour, Acidity Regulator (Sodium Acetate), Flavouring, Colour (Iron Oxides)