Right, that’s not the best option. Kunaki factors in all costs. We are actually hitting their API to get the actual costs.
You could allow the Kunaki generated charge for shipping and add a small fee to cover the rest of your costs. If the customer selects the cheapest shipping option, they are charged the promised flat fee.
This is probably the best method. That’s really what you get with Kunaki-- it's hard to define a specific price. But you get the benefit of never losing money on shipping, allowing your customers to expedite shipping, and also ship international. So I guess that's the trade-off.
Additional keywords: physical, shipment, delivery, kunaki