It seems like people with too much money to spend get a little too excited at celebrity memorabilia auctions.

Last weekend, Sylvester Stallone's custom-built 1955 truck from "The Expendables" (also known as the old-guy action flick) sold for $132,000, TMZ reported.

We'll admit that the truck's "hidden compartments to hold movie weapons" sound pretty cool -- but why would anyone want a clunky prop from a critically panned movie?

SODAHEAD SLIDESHOW: See celebrities' insanely overpriced memorabilia.

But far stranger things have happened at celebrity auctions. For example, a 30-year-old slice of Princess Diana's wedding cake recently sold for $290. And the sexy dress that Marilyn Monroe wore to serenade President Kennedy with "Happy Birthday, Mr. President" coughed up over $1.26 million.

From Stallone's testosterone-fueled truck to Diana's decaying dessert, let us know: What's the most insanely overpriced celebrity auction item?