there was a summer event on zantarni something like this. basically there was a story released every day that had clues in it as to where to find 4-5 sand dollars. And if you got the answer to everything you'd have just enough sand-dollars to get the whole item set that was to be released at the end, but you could use your mule too.
In the end the clues were A LOT of hard work over a week or more and the prizes weren't very good.