[GasHouseGang]

Thanks Al, I read that too. So based on the fact that he bought the cards in the spring of 1986, the ads should have appeared in the summer and fall of 1986 I guess. And I found this on the web which came from Al's book:

I placed an advertisement in Sports Collectors Digest trying to sell the Mantles for $3,500 each, perfectly centered gem mint cards, and I ran photos with the advertisement. I didn't sell any Mantles at that price. I was crushed. So I started blowing them out, and most of them I sold to dealers for $2,000 each.
The last ten I sold to John Broggi of JKJ Sports Collectibles. He paid $12,500 for the ten of them.

That was 1986, right before the major baseball card boom.

He says, six months later, those same Mantles he sold were selling for up to $10,000 each and he wished he could go back in time.

Then a few years later, one of the Mantles he sold to Jim Copeland for $2,000 sold for $41,000 at auction.

He didn't really have much choice because he really needed to make his money back and they didn't sell initially like he thought they would.