About $0.85/gal when I bought my E21 in May, 1979. That was just before the 1979-1980 oil shock, which is when prices broke through the $1 barrier. In the mid-late 80's gas was below $1 again in many places, but that was short-lived. Here are some interesting charts documenting prices paid by a person who has kept records of what he's paid going back 34 years:
http://www.randomuseless.info/gasprice/gasprice.html
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F83 M4 convertible, F15 X5 xDrive35i
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