One extra item can change the whole delivery charge: check the quantity band
By Erik Nilsen · Kroni2 min read
When delivery is priced in quantity bands, adding an item can cost more than its own label if it moves the order into another band. Treat the boundary as part of the budget rather than a checkout detail.
Show the bands before adding an item
In a hypothetical example, optional paper booklets cost 10 units each. Delivery costs 10 for one to three booklets and 25 for four to six. The arbitrary prices and rules are invented, with no other charges included.
Three booklets cost 3 × 10 + 10 = 40 units. Four cost 4 × 10 + 25 = 65. Moving from three to four increases payment by 65 − 40 = 25, although the booklet itself costs only 10.
The extra 25 consists of 10 for the booklet and 15 more for delivery. This is neither a new item discount nor a multiplication error; the order crossed a boundary in the terms.
Recalculate the total when quantity changes
A practical snag is adding 10 to an existing plan costing 40 for one more booklet. Your child expects 50, but the exercise total is 65. With a budget of 55, three fit while four do not.
Five would cost 5 × 10 + 25 = 75. Delivery does not rise again between four and five under this rule, but it is already in the more expensive band. Write the quantity, item subtotal and applicable delivery price on each row.
The stated rule covers only one to six. For seven, request a new confirmed calculation rather than extending the table by guessing. For an actual purchase, check delivery on the completed order before paying.
Ask your family: “Does the new quantity fall in the same pricing band as the old one?”
Carry the calculation into your family agreement
Kroni can keep track of your child's virtual balance. The app does not transfer money, so any actual purchase is paid for outside it. Agree on what you will record, then check the amount with your child afterwards. Do not deduct a possible cost as though the purchase had already happened. Read about allowance in Kroni.
