[Smarti5051]

With about a $1M nest egg for retirement and about a decade to go (and assuming he some day wants to retire), I think the more prudent thing to do is either invest in VTI or pay off the mortgage. If he had $4M+ invested, looking to alternative investments for the sake of diversity would make more sense.

Imagine a scenario where five years from now the 401K is worth $400K because of a major recession and he is a few years away from retirement (or worse, gets forced into retirement due to a bad economy). He still has 5 years on a mortgage, $400K in a 401K he can't touch, and he is trying to sell a very expensive piece of cardboard to a market where most of his customers have just lost 50%+ of their net worth. At least VTI would push out some dividends and he could liquidate small amounts in an emergency.

With that said, is he a big sports card collector? If so, the psychological benefit of acquiring and owning a "grail card" could tip the balance closer to even. But, if that card represents 10%+ of his net worth, then you could have additional costs of storage and insurance. So, unless he is as crazy as most of us on these boards, I don't think it is smart from a financial "investment" standpoint.

I also wonder about the timeline posed in your original question. You say he is 50. You also say he is looking for an investment to "hold" for 25 years. That puts him at 75 when he is looking to potentially liquidate the card. 75 is far from guaranteed to anyone. I am not there yet, but it seems like there is less value in a stockpile of money when you are 75 than when you are 60-65. At least in the stock market, you can liquidate smaller portions of your investment over the years for experiences and things that make your life more enjoyable or easier.