Especially as the years go by, the value of rock artifacts from previous decades steadily rises.

Things that were at one point mere tools — guitars, drum skins, notebooks for scribbling down lyrics — have now become treasured tokens worth tens of thousands of dollars. In some cases, we're talking millions.

Sometimes items are purposefully brought forth in an effort to raise funds for something. Like in 2005, when Bryan Adams arranged for a white Fender Stratocaster — worth a few hundred dollars — to be signed by the following: Mick Jagger, Keith Richards, Eric Clapton, Brian MayJimmy PageDavid Gilmour, Jeff BeckPete Townshend, Mark Knopfler, Ray DaviesLiam Gallagher, Ronnie Wood, Tony Iommi, Angus and Malcolm YoungPaul McCartney, Sting, Ritchie Blackmore and Def Leppard. The instrument sold at auction for $2.7 million, at that point the most expensive guitar ever sold at auction, and the proceeds were donated to organizations working to help those affected by an enormous earthquake along the Indian Ocean coastline.

In other instances, it really is a matter of cleaning out house — a rock 'n' roll yard sale, if you will. In 1998, Elton John told off over 2,000 items from his collection at a four-day auction in London, which brought in $8.2 million.

From instruments to cars to handwritten lyric pages, we're taking a look at 29 of the Most Expensive Rock Memorabilia Ever Sold in the below gallery, some of which sold way above their expected price, while others smashed records.

29 of the Most Expensive Rock Memorabilia Ever Sold

For some, money is no object.

Gallery Credit: Allison Rapp

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