I noticed that the margin percent calculations in Sage didn't seem quite right so to test things I created a brand new average cost item.  I gave the item a Standard Cost of $100.  I then received in 100 units @ $100 each and then another receipt for 100 more units @ $200 each.  I know have an item with a Standard Cost of $100, an average cost of $150 per unit and a last cost of $200 each.  I then go into Sales Order Entry and added this to a sales order with a price of $500 per unit.  Sage shows me the Unit Cost is $150 per unit, the average cost and it also shows me that the Margin % is 60% for that sales order line.  This is not correct.  ($500 - $150)/$500 = 70%.  

It appears that Sage is actually using the last cost per unit of $200 per unit to perform the margin percent calculation as ($500-$$200) / $500 = 60% which is what Sage shows.  My question is why would Sage show the Average Cost and then use the Last Cost to calculate the Margin Percent?