How much is my signed guitar worth?

i have a white glen burton les paul style guitar signed by Bruce Springsteen, Bono, Edge, Keith Richards, Jimmy Page, Angus Young, Carlos Santana, Slash, Tom Petty, Sting, Lenny Kravitz, Billy Gibbons, Richie Sambora, John Bon Jovi, John Mayer, Dave Matthews, Kirk Hammett, Joe Perry, Paul Stanley, and Steve Vai. i got it off an official website with the certificate of authenticity. i was wondering how much it would be worth if i sold it to a store or off ebay. i was also wondering how much a guitar like this would be worth if i sold it 40 years from now. if you want to see a picture of it go to google images and type "legends of rock signed guitar" and it would be in the first two rows.