Value is a perception-based quantification in the guest's mind. It's not something that can be easily measured.
Just because your food cost is the same on every item you serve; doesn't mean the perceived value is the same.
Fine dining restaurants can charge more for simple ingredients based on the atmosphere and the service.
So when you are thinking about the value, you deliver don't just whip out the calculator and add up your cost of goods. Understand the perception of your restaurant. Sometimes you will be able to charge more, and sometimes you are overcharging.