Salad & Water -- vs. -- Quarter Pounder, Fries & Coke

I walked into McDonald's today for a quick lunch "to go".
As I stared up at the menu and was impressed that they offered a "healthy" option combo of salad & bottled water. This lunch included the Asian Salad and a bottle of Dasani water. (By the way, for those of you who don't know, Dasani is "purified" water, NOT spring water)

I said to the clerk, "I wonder why a 'salad & water' costs more than a 'burger, fries and a coke'?!"
She was confused so I pointed to the sign up above, which showed the salad as $6.19 and with tax I had just paid $4.59 for the #2 combo.

Well she didn't know, so she asked another person, who fumbled for an answer, during which, a 3rd person leaned into the conversation and said,
"Because the salad costs more to put together."
"hmmm", I said, "salad, mandarin orange segments and sliced almonds vs. meat, bread, potatoes, and a soft drink... I don't think so. "

Why do they think they need to charge us more just because people are suddenly caring what they put in their bodies?

I'm just not 'buying' it. And so I didn't.... and I won't.