I've been thinking about this a bit recently. I bought a double bass that was owned by Jack Bruce (not in the putative sense most vintage instruments are sold) but with provenance from Bonhams. It's 100% one of his, but it means nothing to me really. I bought it because I needed a great sounding classical bass and this was checked over by a friend and was given the OK. We assumed it would be out of my price range, but in the end it sold for half the original Bonham's sale price.
I guess my point is that the "value" of celebrity ownership is probably temporal and that the celebrities of today are unlikely to mean much (if anything) to the generations in the future. Maybe a few will, but ultimately, we're all shadows and dust. Or 3 generations from irrelevance, as my mum put it when we were enjoying a walk.