Couriers charge in different ways,

Couriers charge in different ways, one on a fixed daily rate, others per order which makes it hard to tell which is actually cheaper. The rates aren't comparable until you convert them to the same measure.

Since the daily dispatch report already tracked how many orders each courier handled, I used it to work out the real cost per delivered order for each one, month by month.

That reframes the fixed daily rate as a volume question: it's the cheapest option at high volume and the most expensive at low volume, with a clear break-even point. It also shows which courier accounts for the largest share of spend, which is where a rate negotiation is worth having.

Cost is only one input. Service quality, delivery speed, handling, and how reliably cash is returned, matters just as much, so the cost figure informs the decision rather than making it.