You're missing the bigger picture. From now on, every homer that Barry hits is a record-breaker.
I was reading a while ago about the estimated value of the 756 ball. It's not as high as many would think. Memorabilia experts are pegging it at around $400,000-500,000, and even less is the Stem doofus waits too long. Several reasons for the seemingly low value:
1. Bonds is a tool.
2. Steroids.
3. Memorabilia market is in a bad way right now, mostly from players milking it for the last decade.
4. This is likely not the "record-setting" HR ball, Bonds's last will be, so the ball from his last will be worth the most.
5. Market figures Bonds will not hold the record for that long, likely less than 10 years.