The issue I'm having is this:
We buy product and store it in our warehouse and sometimes months will pass before we ship. Every quarter the material costs change and therefore I'll have two or three different costs for the same item. In the sub-report (details b) it shows the unit cost based on the the quarter it came from. It multiplies the quantity of an item by the unit cost of that quarter, i.e. 500pcs at Q2 price of $3 and 400pcs at Q1 price of $4; a formula will determine that we have $1500 from Q2 and $1600 from Q1 for a total of $3100. Which is exactly what we want. However, on the main report (details a) it will show a quantity of 900pcs at the latest price (Q2/$3) and show a total cost of $2700. The running total on the main report pulls the data from the latter of these examples and when multiplied over 200-300 part numbers its showing we have thousands of dollars less than what we actually do. I'm trying to achieve a running total based on the running total/formula of the sub-report. I'm not sure if I need it in the details section or what effect it would have if I were to move it to another section.