"Crash Value is calculated from the 1982 base lows with a 7.5% annual rate of return, which is fair considering the dividend cuts we've seen in the past decade."
Why use a starting point of 1982 which is the end of a long flattish market? What number do you get if you use 1968 as the starting point? For the S&P was about the same in 68 as in 82.
A more interesting calculation would be inflation adjusted returns, let's say 2% over inflation rate each year instead of a simple 7.5%.
Taking your S&P 490 number and compounding it for another 13 years @ 7.5% (to make the starting point 1968 vs 1982) I get 1254...could be S&P is undervalued here.