Surely I am not alone in this crowd when I say the "Highlander" antiquities dealer approach to making a buck with immortality always struck me as highly inefficient... and potentially not even profitable in the long run!
Sure, by holding on to random stuff for long enough along your immortal life some of them will eventually become very valuable.
However, what always bothered me was: what about the warehousing costs across the centuries or millenia?!?!
Furthermore, since you never know what will eventually become priceless and what will become worthless, what are the losses on warehousing dud items for centuries that are either worthless or whose appreciation over time is still well below the costs of storing, guarding and preserving them?!
Heck, I bet even something like King Tutankhamun's jewelry would be worth more today if it had been sold at the then market price in the 14th century before Christ and put in a compounding interest fund, than it's current historical-value antiquity market price.