How do you buy signed stuff with confidence?

[Mike1888]

I have a few Kojima-signed items. Generally I try to figure out the event the seller got it signed at (often it will align with their location) and also compare the signature in question to confirmed signatures. I used to use an image that had a timeline of Kojima signatures and showed how it changed over the years - it helps that Kojima dates his signature. Obviously you can never be certain though.