Recipe Costing and Unit Conversion

This could be become a great professional kitchen tool. The obvious forthcoming picture uploads and in phone editing are of course much anticipated. The ability to input the cost of ingredients, and a unit conversion bit would make it the most useful app ever (for me). It should be able to calculate the cost for each amount of each ingredient the recipes. And a simple way to convert from grams to ounces, liters to quarts, etc. Can't iPhone figure that out? I'd pay an extra $20.