I've run into this situation also. One place I stopped at had a special: Burger w. Potatoes and Soda for $x. Don't remember the exact price. I asked and it turned out if I wanted just the burger it would be $1 more than the burger, potatoes, and a drink [because the burger wasn't the special.] So, I ordered the special, left the potatoes, and asked for unsweet tea, to which I added Stevia.