[Fred]

Assuming the OP is asking about the "rookie card craze" rather than cards noted with "rookie" on it, then here's what I remember:

I'm going to guess the REALLY crazy prices started somewhere in the early 90s.

I remember a dealer busting open cases of 84 Topps (the year the cards were released) trying to pull the Mattingly's so he could sell them for a couple/few bucks apiece. I thought the guy was nuts and anybody buying them was even crazier. I think things really got going with the Griffey Jr. 89 UD rookie cards. After that things went out of control.

I can still remember dealers selling 84T wax football cases and couldn't get more than $100 bucks a case (right after the football season ended), then people started trying to get the Marino's and Dickerson's. Somewhere in the early 90's those same wax 84T football boxes (not cases) were going for over $100 each because of the Marino rookie cards.

Old Beckett guides might provide a good clue regarding the time frame when things got stupid.

I never bought into the modern era rookie card craze because the thought of paying a ton of cash for a card where there were probably millions minted just didn't make any sense.

It looks like the "rookie card craze" did have a pretty big influence on market prices for "rookie" cards of vintage era players.

All of the above is from a memory that seems to be getting cloudier as time moves on.

Just for the heck of it I just checked on PSA10 89 UD Griffey rookies on fleabay. PWCC sold 5 different slabs for between $505 and $560 on 27NOV19 (alone) on fleabay. If I read the PSA pop report correctly, there are over 24,000 PSA10 89 UD Griffey cards graded. Pretty crazy stuff.