I'm curious as to whether you guys think vintage game used baseball memorabilia has room to grow in value?

I recently came across a Willie Mays game used bat from the early 60's. Has PSA/DNA authentication and is graded a 9. The seller wants about $10,000 for it. Do items like this have room to increase in value or have they just about hit their max, since it's already been roughly 55 years since it was used?

This particular example had me especially interested because Mantle gamers go for $30-$40k. Mays seems very undervalued compared to the Mick. And I know this is mainly because Mantle played for the Yankees and won 7 World Series' and multiple MVP's, but I still find it hard to believe that Mays' stuff is this low in value compared to him.