Heritage Auctions is offering the earliest-known Britney Spears autograph — from a first-grade yearbook — for $3,000.
No telling if it will fetch that, or more, but I also have a pretty early example.
Before her music was officially released, I interviewed Britney in 1998 at the Jive Records offices. It was a longish chat and she was adorable. She urged me to come see her perform on a tiny stage by Macy's, but I skipped that. I did, however, have her sign her advance sampler, which itself is probably somewhat rare now.
Seems odd to think about an ancient Britney autograph, but remember: Britney came out in 1998, which means she is to today's music as the Supremes were to the music of the '80s!