I am trying to apply a multiplication factor that would vary depending on the
sum of a particular cell. For example let's say the value of cell A5 is the
SUM of A1:A4. Let's say the value is 255,000,000.

my multiplication factor table looks like this:

1 - 50,000,000.........................(0.17)/1000
50,000,001 - 100,000,000..........(0.13)/1000
100,000,001 - 250,000,000.........(0.10)/1000
250,000,001 - 500,000,000.........(0.08)/1000
500,000,001 - 750,000,000.........(0.07)/1000
750,000,000 ++ .......................(0.05)/1000

So depending on the range the cell sum falls into I need the formula to
apply the appropriate multiplication factor and divide by 1000. I'm trying to
avoid manually inputting the (0.XX)/1000 based on the formula identifying
which range the sum falls into and automatically applying the appropriate
multiplication factor. In the example above the formula would be applied to
the A6 cell and identify the A5 sum as falling into the "range" and
automatically apply the corresponding multiplication factor.

Is something like this more advanced than what Excel can handle?

Thanks in advance for any perspective on this.