McDonalds is still dirt-ass cheap, that's how they mainly get by. Sure, their combos aren't much cheaper than any place else, but where else can you get a double cheeseburger(McDouble), a chicken sandwhich(McChicken) and a large drink for 3 bucks? Thats a hell of a filling meal right there, and its 3 bucks(its also like 1000 calories). You can't even get a 6-inch sub at Subway for 3 bucks anymore, much less with a drink.
It's almost shocking how expensive fast food is anymore if you really look at it. Subway has like 2 sandwhiches that are $5 footlongs anymore, most of their footlongs are $6.50 - $8.50, if you add chips and a drink you're up to 10 dollars easy. A big roast beef at Arbys is like 4 or 5 bucks just for the sandwhich, 8 or 9 if you want it as a combo. A whopper combo at Burger King is like $7, etc. I don't always eat just off the value menus, but Mcdonalds you can legitimately get a LOT of food for like 3 bucks. Its crazy. That just shows you how low quality it really is.