Why your 3-pack costs almost the same to ship

Where the steps are

Two fulfilment costs don't grow in proportion to what is in the box. A shipping label is priced by weight in whole-pound steps, so a second or third item often rides inside the weight the first one already paid for. Pick and pack has a charge for the order and a much smaller one for each extra item.

A sheet that multiplies the single-unit shipping and handling cost by the quantity misses both. It prices a three-pack as three parcels.

A worked example

A bottle of supplements that packs at 0.5 lb. USPS Ground Advantage at commercial rates, Zone 5, charges by the pound: 1 lb $9.29, 2 lb $10.50, 3 lb $12.12. A warehouse charges $3.20 to pick and pack the first item and $0.48 for each extra one.

One bottle ships for $9.29. Three bottles weigh 1.5 lb, go on the 2 lb label and cost $10.50: $1.21 more for two more bottles. Label and picks together are $12.49 for one bottle and $14.66 for three, which is $4.89 a bottle.

Multiplied out, the sheet puts $27.87 of labels and $9.60 of picks on the three-pack, $22.81 more than it costs.

The order's figures are computed by the margin engine in Offer Suite's own code, in whole cents. The sheet's are the same order with the mistake applied.

What it does to the bundle price

That difference is the room a bundle discount comes from. At list price and with shipping free, one bottle keeps 30.8% of what the customer pays and three keep 51.4%. The three-pack can give part of that back as a discount and still earn more than three single orders would.

The steps cut the other way at the boundaries. The fifth bottle crosses into the next pound and adds $1.62 of label, where the fourth added nothing. A pack that sits just under a weight step ships for less per unit than the next size up, which is worth knowing before choosing between a four-pack and a five-pack.

A sheet that multiplies overstates what every bundle costs, shows thin bundle margins and argues against discounts that would have paid.

How Offer Suite costs a parcel

Offer Suite's cost ledger has a grain for each of these. A cost kind is charged per unit, per parcel, per order or as a percent. The label is a per-parcel kind, looked up in a freight table by the parcel's total weight rounded up to the pound, and the extra pick is a per-unit kind that applies only to the units after the first.

So a bundle is costed as the one parcel it is. The bundle pricing calculator costs a bundle as one order on your own numbers, and the playbooks work bundles through for each vertical.

A spreadsheet is still the right tool for some of this. Where it is, and where it stops: Offer Suite vs a spreadsheet.

Where the numbers come from

The example is not a real brand's offer. The packed weight of 0.5 lb a bottle is an assumption. Every other input is sourced below, or marked there as an assumption.