These are known are brutally hard to find – and pricey too. One sold several months ago for $290.00. There are actually four of the Musical Jars, the others being Peach, Yoshi and Toad. There is a cool unboxing video here if you want to listen the music.
Toad sold loose awhile back for $104.38 and I know Peach has sold for $275.00 Boxed (although one was listed for much cheaper recently and did not sell).