Somewhat related, I went to Souplantation for the first time in my life last week. Now that's a good salad bar. For $11, I could go there for sure and get a good salad on the regular, plus some soup and whatever else.
They key is moderation, as someone said earlier. All you can eat buffet immediately inspires people to stuff their faces, when really you can stop whenever you want. Always the hard part in diet.