I think it's pretty cool actually. If you expanded this to different restaurants, you may have something on your hands. I can't tell you how many times I've gone through this scenario when ordering. Not at McDonalds, granted, but at the places I do frequent.
Yes, it might be useful providing a real dataset... The problem would be finding the menus and making sure prices are correct, etc. That would need to be crowdsourced, and I'm not sure that many people would be willing to participate. :)
Agreed. You could form it into an app where you input how much cash you have on you and you find local restaurant items (or any other kind of product actually) that you could afford.
