If we presume he's never going to sign "4x SB" ever again, wouldn't that help to date the autograph to a particular time?
Probably, but it wouldn't necessarily be a good selling point. You have an inscription (a very expensive one) which is no longer accurate. Fans are going to opt for 5x (or whatever he ends up with).
He'll probably end up charging that much, at least for a while. Jordan was (and is) a much bigger cultural icon who was known very well worldwide, so that might be the difference here.
Ho, Jennifer. Did you mean to post a photo?
You might want to scan it if you can for a clearer image. I'm not particularly good with Brady autographs, but I know there are few others here who are.