I have so much in my bag, and I want money, so is there a maniac for flutes? If yes, where is he?
In Undella Bay go to the huge mansion on the left of the town, the riches mansion . Inside there will be a man similar to a karate guy (xD) and he will buy it for 7500 Pokedellars. It's the same man that buys the relic items as well.