Throwing another pricey-but-wears-well brand into the fray: Keen. I get 4-5 years a shot out of any given pair of their Mary Janes. They skew wide and the footbed is hella comfortable. (I don't know if they offer replacements themselves, but the footbed is removable.)

Keen sell directly and Zappos carry their line, but it's worth hitting a brick-and-mortar shop at first. Some people don't get on with the footbed.