Weird pitch, would you guys be able to cook your own meals or eat out for a week?
As in, don't use anything you didn't buy yourself for a week just to get an idea. Obviously that is not going to help you save up for your place, but the research might be worth it.
Also if you still live at home use this time to consider what you use to cook (pots, pans, utensils, etc)
I had no idea what food costs were until I moved out, I learned the hard way that I had to learn to cook or my budget would be forever broken, but grocery costs and budgeting are a whole other skill so it isn't automatic that shopping and cooking will be cheaper if you don't shop carefully.
Good luck, the very fact that you are thinking about this ahead of time is a good sign!