The 1980 peak of $850 would be roughly $2235 in 2010 via “official” (i.e. lower than actual) CPI alone via the BLS Inflation Calculator here http://www.bls.gov/data/inflation_calculator.htm
Inflation numbers more like what we actually see, per SGS here, are roughly 2% higher than BLS numbers in their graph going back to 2001. If we say that “real” inflation is 1% higher than “official” inflation over 32 years, that’s 1.01^^32 = 1.37; the 2% boost would be 1.02^^32 = 1.88. That adjustment itself would boost that $2235 to somewhere in the neighborhood of $3061 to $4200.
So realizing inflation alone gets it more than half of the difference from here to there, before pondering how much more screwed up the monetary system is now than it was in 1980.
oops here’s that SGS link for 2001-2010 (second graph) http://www.shadowstats.com/
and from 1980-2010 http://www.shadowstats.com/alternate_data/inflation-charts Note that the very visible divergence begins in 1983