What is an autograph without a certificate worth?

Answer 1

An autograph is typically considered "priceless". This covers many fronts, it could be worth a lot of money to the general public or it could be worth nothing.

Generally an autograph is worth as much as someone is willing to pay for it, and this obviously, is an indeterminable factor.

To answer your question more directly, the bigger the "celebrity" of the person, the higher the value, although you will find an autograph on its own is not worth nearly as much as an item autographed by a person.

(example, a football signed by Wayne Rooney would raise much more money than a mere autograph from Wayne)