The Cubs-A's Eckersley trade also doesn't belong in the same category, not even close. Eck was 32 in 1987, had been either ineffective, or hurt, or both, for about 6-7 seasons. In 1986 he was 6-11 with a 4.57 ERA in 33 starts. No one - absolutely no one - thought the Cubs were getting raked in that trade at the time.
As it turns out, Eck was about to go on a 5-year run that ranks with the best of any relief pitcher in history, but no one foresaw that in April of '87, including the A's....