Also note that the price ranges on the Disney website are not specific to a particular restaurant. They are "buckets" that Disney uses to categorize ALL of their restaurants. So, every restaurant with an average adult dinner within that price range will show that entire range (and the matching dollar sign icon's that go with it).
You can see this in action if you select a date and a dinner time for ADRs, but don't input a restaurant. You'll see that the vast majority of them fall into two categories ($$ and $$$) and that all the restaurants within the same category will show the same price range.