I started buying up Jeter minor league rookie cards when he was still in AAA. I probably had 100-200 at one point before 1996. After he won ROY and the Yankees won the 1996, 1998 and 1999 WS, I went to "cash in" my Jeter cards. I made a little money, but because PSA came to the fore front in the interim, and none of my Jeter's woulda graded a 10, I was basically able to earn a couple hundred dollars.
Given how well I predicted (guessed) the Jeter phenomenon, I always thought that my early minor league purchase decisions should have been rewarded like a lottery ticket..... but no such luck!
Also, bought 50 Frank Thomas 1990 Topps rookies while he was still in college on a hunch. Cost me $.25 per card. Wound up selling most of them for $4. The Leaf was the way to go, not the Topps. Made a couple hundred, but shoulda made a bank!
Oh well!