Definately go to Casey's Place for lunch. It has become a favorite of ours.
It is in town. GREAT home made sandwiches, great hot dogs, french fries, blt's, etc.
You walk up to it. They have picnic tables to eat at. We do this at least once every time we go and then get a Rita's Italian Ice for dessert-also in town.
If you are not going to drive into VB then anywhere at the resort is good for lunch. We like Bleacher's out by the pool-I wouldn't classify it as cheap though.