Here are my complete ICM calculations:

You fold (Stacks are 5M, 1M, 150K)
$EV = 1000000/6150000 * $1000000 + ( you take 1st )
5000000/6150000 * 1000000/1150000 * $500000 + ( BigStack takes 1st, you 2nd )
150000/6150000 * 1000000/6000000 * $500000 + (ShortStack takes 1st, you 2nd )
5000000/6150000 * 150000/1150000 * $250000 + (BS 1st, SS 2nd)
150000/6150000 * 5000000/6000000 * $250000 (SS 1st, BS 2nd)

$EV = $162611 + $353482 + $2033 + $26511 + $5081

$EV = $549718

If you double up (Stacks are 4M, 2M, 150K):
$EV = 2000000/6150000 * $1000000 + ( you take 1st )
4000000/6150000 * 2000000/2150000 * $500000 + ( BigStack takes 1st, you 2nd )
150000/6150000 * 2000000/6000000 * $500000 + (ShortStack takes 1st, you 2nd )
4000000/6150000 * 150000/2150000 * $250000 + (BS 1st, SS 2nd)
150000/6150000 * 4000000/6000000 * $250000 (SS 1st, BS 2nd)

$EV = $325203 + $302515 + $4065 + $11344 + $4065

$EV = $647192