When you got money to blow ... why not spend it on a nickle?

Sounds ridiculous.

An American nickle is worth $.05 ... so who in their right might would spend $4.5 million on one. Well, apparently this rare coin is currently worth that much and someone just bought it in Philly.

Insane. This American nickle is dated back to 1913 and is one of five of the Eliasberg Liberty Head edition and was sold at the World's Fair of Money auction last night.

According to phillyvoice, the new owner, "now possesses one of the rarest, most valuable United States coins," says Brian Kendrella, president of Stack's Bowers Galleries.