Like Pellius mentioned, if you use the App, you can get the stuff almost free.
Last time I went, I got a QP w/ cheese for 3.50, and a 2nd one for 1.00, and a small milk, Twas like 5.00 and change.
Haven't been back since cleaning up the (hate the word "diet") eating habits again, but now I want a QP and a Big Mac god dammit!

Last 6 times out to eat was Chinese a couple of times, Korean, Thai, etc. You can get the healthy lunch meals for 6.50 (with one junk side like chicken wings that come w/ it).
Of course if Mai-Tai's come into play, its no longer a cheap meal.