The one-page answer to "what will this cost me"

Cost by weight band excluding item value, plus the three cases where the table fails. It comes from the 96-entry census, and the method behind it is documented rather than implied.

Where the money actually goes

Six segments make up the landed cost, and only the first is the item itself. For a t/shirts order in our sample the average item value is $29.09, against $7.50 to $74.40 of everything else. That ratio is the single most useful number in this reading.

The six segments, with their sample ranges
Segment	Range	What moves it
Item value	$12.52–$168.48	Catalogue mix
Domestic delivery	$0.40–$3.10	Weight band
Service fee	$1.20–$9.80	Fee model, order value
International freight	$5.90–$9.40 at light (< 0.8 kg)	Billed weight, lane
Duty	$0.00–$17.40	Declared value, destination
Insurance	$0.00–$2.60	Declared value; optional

Item value is a published figure read from the source listings. The other five are modelled ranges and are labelled as such wherever they appear.

Read the table by column, not by row: the segments with the widest ranges are the ones worth spending attention on, and the widest by a factor of three is international freight.

Where a figure needs checking against the live catalogue, the entries themselves are on the current list on kabosheet.

Sensitivity, ranked

Four variables carry almost all the sensitivity: billed weight, declared value, lane and item value. Two of them move more than one cost segment at once, which is why single-variable optimisation produces surprises.

Billed weight moves freight, and only freight — but by a full band.
Declared value moves duty and the compensation ceiling together.
Item value moves the service fee, and only under a percentage model.
Lane moves freight and transit; it does not move duty at all.

On the reference lane a light (< 0.8 kg) parcel quotes $5.90–$9.40. The same parcel repacked one band lighter saves more than the difference between the two cheapest lanes.

Sensitivity ranked by effect on the total
Variable	Segments moved	Typical effect
Billed weight	Freight	One full tariff step
Declared value	Duty, ceiling	Up to $17.40
Lane	Freight, transit	$3–$9 plus 7–8 days
Item value	Service fee	1–3% of item value

Ranked from the census distributions; individual orders vary.

What each budget band really buys

Budget bands behave differently because fixed and variable costs swap places as the order grows. At $150 the fixed components dominate; at $900 the item mix does.

The three budget rungs
Budget	Items	Dominant segment	Main risk
$150	3–5	Fixed costs	One heavy item moves the whole order a band
$400	6–10	Freight	Declaration accuracy and the 8 kg boundary
$900	12–20	Item value	Handling tier boundary; splitting becomes cheaper

Ranges derived from the census distributions, not from individual orders.

At the bottom rung, adding a fourth item often costs less than the freight you would pay to ship it separately. At the top rung, adding a fifteenth item can cost more than the item.

At $150: One seller, one parcel, no express. Consolidation has nothing to consolidate.
At $400: Consolidate, and confirm the declaration before paying freight.
At $900: Plan two parcels from the start rather than discovering the tier boundary.

Declared value and its two consequences

The declared figure sets two things at once: the duty the parcel attracts and the ceiling on any compensation if it is lost. They cannot be optimised separately, which is why the choice is a decision rather than an entry field.

Declared value against its two consequences
Declared value	Duty modelled	Compensation ceiling
Below destination threshold	$0.00	Equals declared value
Just above threshold	$0.00–$6.00	Equals declared value
Well above threshold	$6.00–$17.40	Equals declared value
Under-declared	Lower	Lower by the same amount

Modelled from published thresholds for the four destination regions. This is not tax advice; verify current rules for your destination.

Estimate error concentrates near thresholds. That is a property of the rules, not of the model: a step function produces large effects from small changes exactly at the step.

Declare accurately and keep the order record. A plausible figure with evidence survives a claim; a precise figure without evidence does not.

Why the packed box decides the bill

A parcel bills on the greater of scale weight and volumetric weight. For a light (< 0.8 kg) item the two are not close: packing decisions can move the billed weight by a full tariff step, and 31 of the 96 orders in our sample changed freight at the rehearsal stage.

Packing effect on billed weight, worked cases
Packed dimensions	Volume	Volumetric weight	Billed at
30 × 20 × 10 cm	6,000 cm³	1.20 kg	Scale weight if higher
38 × 28 × 22 cm	23,408 cm³	4.68 kg	Volumetric
44 × 32 × 26 cm	36,608 cm³	7.32 kg	Volumetric
52 × 38 × 34 cm	67,184 cm³	13.44 kg	Volumetric, two tiers up

Calculated at the 5000 divisor. Some carriers use 6000 or 4000, which changes the result by up to 20%.

The fix is not to switch lanes; it is to ask for packed dimensions before paying freight. One of the parcels we recorded went from 2.1 kg on the scale to 6.8 kg billed, entirely because the seller chose a box.

Ask for packed dimensions, not item dimensions.
Request compression where the category tolerates it.
Check the volumetric weight before paying, not after.
Remove one bulky item rather than changing lane when a parcel sits on a boundary.

Who is responsible at each stage

A parcel changes hands eight times between payment and doorstep. Each handoff has an owner, a typical duration and a failure mode, and knowing which is which is what turns a support ticket into a specific question.

Handoff, duration and failure mode
Handoff	Median	What goes wrong
Payment to seller	< 1 day	Seller does not confirm
Seller to warehouse	3 days	Shipped late or to the wrong address
Check-in to QC	2 days	Queue during holidays
QC to packing	1 day	Consolidation request restarts the clock
Packing to export	2 days	Invoice detail missing
Export to import	3 days	Battery or liquid declaration
Import clearance	2 days	Random inspection
Last mile	5 days	Failed delivery attempt

Medians from the 96-order sample.

The two highest-leverage interventions sit at opposite ends of the chain: a 72-hour rule on the seller, and an address check before the freight payment.

Set a 72-hour rule at the seller handoff and act on it.
Write the QC verdict down before looking at the next photo set.
Submit consolidation before packing, not after.
Confirm the destination address before paying freight.

Ownership at each handoff

Eight handoffs separate payment from delivery, and each has a nominal owner. One of them — the QC verdict — has no owner at all: the warehouse takes the photographs and you decide what they mean.

Payment to seller: Agent owns the transaction; you own the accuracy of the buy request.
Seller to warehouse: Seller owns dispatch; agent owns follow-up.
Check-in: Warehouse owns registration; the storage clock starts here at some agents.
QC: Shared and therefore ambiguous — the only genuinely unowned step.
Packing: Warehouse owns dimensions; you own the consolidation instruction.
Export: Agent owns documentation; you own supplying complete details.
Clearance: Carrier owns the filing; you own the declaration.
Last mile: Carrier owns delivery; you own address accuracy.

Tail risk concentrates at the seller, the clearance desk and the doorstep. Two of the three are entirely within your control before you pay.

Median and p90 at the three longest handoffs
Handoff	Median	p90	Tail cause
Seller to warehouse	3 days	8 days	Seller does not confirm
Import clearance	2 days	9 days	Random inspection
Last mile	5 days	15 days	Failed delivery attempt

From the 96-order sample.

Economy against express, held constant

Comparing lanes only means something if the parcel is held constant. One parcel, one weight band at a time, one item mix — anything else is a different question with a different answer.

Economy against express, US lane
Weight band	Economy	Express	Difference
1.5 kg	$5.90–$9.40	$11.40–$17.20	+$5.50
3 kg	$9.20–$15.10	$17.10–$26.40	+$7.90
5 kg	$14.80–$24.30	$25.30–$39.70	+$10.50
8 kg	$22.60–$36.90	$36.20–$57.10	+$13.60
12 kg	$31.40–$52.80	$48.90–$78.40	+$17.50

Modelled from published tariffs on the collection date.

Express buys eight days at 1.5 kg and seven at 8 kg, for two and a half times the money. That is the entire case for choosing on weight rather than on urgency.

At 1.5 kg: About $0.69 per day saved — a deadline makes this obvious.
At 8 kg: About $1.94 per day saved — a different week is the better lever.
At 12 kg: About $2.50 per day saved — a second parcel or a later date wins.