i was told by a cast member a couple years ago that they were "discontinued" and were only available in the candy shop on mainstreet and it was a fill-your-bag dealio. but i went back a less than a year after that and goofy sour balls were back, but in my opinion they don't taste the same. maybe they changed their recipe or something, but i like the old ones better.
i was also told that there is/was another candy (can't remember the name-- something mad hatters?) that's basically the same as the sour balls. never tried them, so i don't know how they compare.