Different vendors sell ingredients for different prices, so you could lose money if you don't have a good source for your ingredients. Some dishes should just be saved for specific characters and not sold to the normal customers.

Also, additions do not change the price of anything you sell, they just improve your rating which affects how much your customers order and tip.

Damn, there are a lot of useless recipes then. wish there was a blacklist option to hide them. I only kept the kaguya-hime on the menu for the competition, and it won by a landslide, but man does it cost way too much to make. The turkey is so much better cost wise but nobody orders it.

Not that i'm hurting for cash or anything, I have much more than I need, but it's principle that counts

The final amount of money you can get may not necessarily be the price listed on the recipes, as there are tips and various additional bonuses. Moreover, customers' evaluations are based on the tags on the recipes. If you are not so concerned about this but pursue profits purely in terms of money, then some recipes may indeed not meet your expectations.