I am trying to develop a spreadsheet that calculates the production cost of a certain item, based on the # of orders for the item.

One of the widgets that is part of this item costs $2 per unit, but with a minimum order of 250,000 widgets.

So let's say I have an order for 200 items.

The variable cost for the widget would be 200 x $2 = $400, but then I have an additional cost of 50 X $2 = $100, since I cannot order just 200 widgets.

But then if my order changes to 300, my variable cost would be 300 x $2 = $600, but then my additional cost would be 200 x $2 = $400.

I cannot come up with a formula for this additional cost that fits any scenario. Can someone help?

Thanks