I am creating a P+L and need a formula for this instance. I am reasonably
profficient on this software but have never had to generate a spreadsheet
like this.

Could someone advise a formula for this instance:

I have a units sold column which generates the rest of the P+L, but there
are some variable fields. 40,000 units are ordered no matter what, and then
any amount over this would require a reorder, but this can only be done in
multiples of 2,500. so if I enter 51,000 in the units sold field, i need the
order costs to calculate an order of 52,500 as it would not be possible to
order any less. The unit costs are not variable (ie there are no economies of
scale benefits) so it is just a matter of making sure the units sold amount
generates an order amount which is possible due to the minimum reorder level.

Any assistance on this, even a link for further advice would be much
appreciated.

Lewis