Why can't bakers provide a ball park number?

This may sound really ridiculous to some people, but I went to a local grocery store bakery and asked them about wedding cakes. They gave a catalog of what they could do, and it already had the prices in it. I designed my own cake (which ended up being BEAUTIFUL) and only paid $175 and that was to feed 200+. I got a great deal, and there wasn't any dancing around the price. I saw the price in the catalog, and even with the few changes I made (just some minimal decoration) I paid the same price. It was delicious and saved me a LOT of money over going to a traditional bakery. I am happy I did it like this. :)