Well, I see I might have a mistake, but not the one you show.

Not sure why we're different here on shrink. I got my numbers from memory & from Iowa St, though we farm in NE IL. They say the following:
12% = 1.2% shrink loss
11% = 2.25% shrink loss
10% = 3.3% shrink loss (my example used for equation)
9% = 4.4% shrink loss
8% = 5.4% shrink loss

Link to ISU re. bean shrink

I don't know if these numbers are cast in stone, but they're better than pulling numbers out of the air.

But, you use 4.4% on 10% moisture. ISU says 3.3%, which is what I used hence my example answer of $14,784 on 500A, that being 1/2 of the acreage too dry. So, you have roughly $15,000 to use towards a 2nd combine, cart, operators, & trucks needed. Justifiable?

Here's my mistake I forgot....if any of the beans were combined at 14% and binned with the 10% beans, it makes for less shrink loss, though now we may start pulling numbers from the air. I would guess we all have the moisture records of our bean harvest showing moisture so you can see the average moisture for your own total harvest.

If you say you leave 5 bu/A on the ground (= 750,000 plants per acre if seeded) then that's what it is for you. But I can assure you that not everyone leaves that much and it has nothing to do with daunting character. I am aware that beans also shatter at 14%. Beans even self-shatter if they get real wet, then dry & windy but still testing 13+. I know that. The hula-hoop method of counting beans on the ground still works.

Again, is the 2nd combine justifiable at these numbers? That was the original point. Am I still "not even close"?