A homemade cupcake versus a store-bought cupcake: the details!
Here are the top 3 main facts:
1) Ingredients: Ingredients are costly, esp. dairy. I make my own cake, I do not use a cake mix. Many large chain grocery stores will use an "all-purpose baking" mix from a box, "just add egg and water" brownie mix, or frozen cookie dough. Why? To keep product control correctly. Not only are the baking goods for their store, but every other store will have to have the exact same treats.
Also, since they use mixes, we never "know exactly" what goes into your cookies, brownies, and breads. Some mixes will have extra special ingredients that are not-so-great for your body.
2) Time: It takes more time to create, mix, and bake cake versus dumping cake mix in a bowl and baking it. Plus, since I always butter my baking dishes (versus using a non-stick spray....ewww.), that action takes more time. And well, time IS money in a large business.
3) Custom decoarting: I always custom decorate to the host's special request. I may be making mini roses on top of mini cupcakes, baking cookies for a nice cupcake topper, or add toasted nuts for a crunch!
Most grocery store will be limited in custom decorating. If you do request something extra special, they may not have a staff member that is able to do it.
I know price is an issue when buying delicious baked goods. There are many local grocery stores that are, now, carrying in-house baked goods and making custom made cakes. Make sure everything is MADE in-house, not just BAKED in-house.