[zljones]

I have obtained some old "Sports Card Americana" price guides by James G. Beckett from between 1979-1995. I have been doing my own personal research on the history of baseball card valuation, and I came across something puzzling, the 1967 Topps Brooks Robinson card had an HBV of $50 making it the most valuable 1960s card back in the 1979 issue #1 of "Sports Card Americana." It far surpassed any 60s Mickey Mantle cards which were only worth about $25-$30 back in 79.
My question is to anyone that collected back in the late 70s, why was the 1967 Topps Brooks Robinson so sought after in 1979 above all other 1960-1969 Topps cards? He was retired by 1977 and made the HOF in 1983 so I am puzzled about why this card was so hot in 1979?