Now the dimensions Each bill is 2.61" (.2175 ft) width X 6.14" (.511 ft)length X .0043" (.00035 ft.) thickness. That means each bill consumes .00000398 cuft.
Now the stack. I noticed that they are using 4 pallets as a square. Since each pallet is 4' X 4', and about 4' tall, this estimates the stack of cash to be about 256 cubic feet.
Divide 256 cubic feet by .00000398 cubic feet per bill means that there are 64,321,608 individual bills.
Now using the 40/20/40 assumption........ 25,728,643 $20 bills equals $514,572,860. 12,864,321 $50 bills equals $643,216,080. 25,728,643 $100 bills $2,572,964,300. Grand total...... $3,730,753,240. Saul better get busy trying to laundry 3.7 billion dollars.
Now some adjustments though..... Air space between bills is obviously going to make this number smaller, but I'd guess Heisenbergs got easily 1 or 2 billion in that stack if the denomination ratios are close.
For futher consideration. I realized that the weight of the higher bills in stack are going to compress the lower ones. I think $2-3 billion is more likely.
How much was in the pile was discussed here:
http://www.businessinsider.com/how-much-money-walter-white-made-on-breaking-bad-2013-8
$80 million