Autograph values are based on many factors. Scarcity, demand, condition of the item, and authentication are all important characteristics.
Inscribed items that are made out to a specific person's name are generally of lesser value than basic signatures (unless your name matches the inscription!).
On the other hand, inscriptions that relate to the signer's accomplishments (MVP, Hall of Fame, etc.) can increase the price of the signature significantly. Some players at autograph signings limit or eliminate inscriptions altogether.
The price of an autograph if a person dies increases, and generally continues to increase in value the longer the person has been deceased. If the demand of the signature continues to increase, so will the value.
Authenticity
of the item is critical in today's hobby. If you are collecting solely for sentimental reasons, it may not be your first concern; however it makes sense to protect your investment in the long run.
The Sanders Autograph Price Guide is considered to be the primary source for information on autograph values for celebrity and sports autographs.
Tuff Stuff and Beckett also produce monthly and annual price guides relative to sports cards, autographs, and signed memorabilia.
You can also get a decent idea of up to the minute information on autograph prices by searching auction websites such as
as well, and seeing what similar items are going for in auctions and buy it now listings.
The context or relevance of the autographed item plays a large part in autograph valuation. For instance, a basketball signed by Michael Jordan is going to be worth more than a football would be.
Like anything else in a marketplace - the value of autographs ultimately comes down to what someone is willing to pay for it. The popularity of the signer to you is sometimes the overriding and most important factor.