Ooh, I love the soft mall pretzels... where I live it's the Auntie Anne's chain. Same for you? Their nutrition info is
here. Most of the pretzels seem to be about 300-500 calories each. A McDonald's
double cheeseburger is about 460 calories, so about the same as one pretzel (!) in that respect, but it's got a TON more fat than a pretzel. So a pretzel is certainly better than eating two double cheeseburgers, but probably not the healthiest lunch choice you could make.
Edit: One McDonald's double cheeseburger gives you 55% of the daily recommended value for saturated fat!

That should be illegal!
Hope that helped!
Sifen