As a new collector I wonder will my autographs increase in value or not. This led zeppelin fully signed cover isn't mine but it has a 20k price tag. Will it appreciate in time?  How many fully signed Zepp covers are in existence?

If anyone who has a story where they made money on their autographs, purchased 10 years ago and know its worth such and such or sold, please share and post the pics. I wonder if I should buy more autographs or invest in something else.