This is one very rare and special item. Only an estimated 10~20 were ever made, and they were all made exclusively for Shigesato Itoi himself. At the Mother 1+2 Release Party Shigesato Itoi gave a few of these out as door prizes and a few close friends. The actual size is unknown. They are made out of plastic. Over the summer of 2003 on a Japanese auction website one of these was auctioned off for an estimated 18,000 Yen, which is about $165.
Recently the Mr. Saturn Statue has been appearing on Shigesato Itoi's webcam. This caused some speculation that Mother 3 was on its way. This turned out to be true. Whether Itoi intended Mr. Saturn for that purpose is unknown, but it definitely reminded everyone of the long awaited sequel. More information and pics about this webcam sighting can be found here.
Very special thanks to Jonk for providing some information and pictures.
How To Get:
Statue - Statue - Statue (Many) - Giveaway (Itoi) - Giveaway (Many) - Ceiling