By Daniel Kline Two of three leading fast-food chains are offering meal deals with multiple entrees as well as fries and a drink (but prices are rising). Fast-food chains have to balance value and profit margin. Customers want to get a lot of food for their dollar — that’s a pretty basic part of the experience — and they want to deliver that while also protecting the bottom line. That’s a challenge McDonald’s (MCD) – Get McDonald’s Corporation Report has wrestled with dating back to its famed Dollar Menu. The idea behind the Dollar Menu was that customers would order their normal meal (likel…