The short answer
Compare fully loaded monthly cost for the same operation, not headline pick-and-pack pricing. A cheaper first-item fee can be outweighed by packaging, minimum shortfalls, storage or postage. Keep one-time charges and recurring costs separate.
Build a representative month
Give every provider the same orders, average items per order, SKU mix, inventory footprint, inbound volume, returns and project work. For shipping, use actual destination ZIP codes, packed dimensions, weight and service requirements. Repeat the comparison for quieter and peak months.
If a proposal uses different units—per SKU versus per unit, bin versus pallet, or hourly versus per carton—translate each into quantities for that same month. Ask for clarification rather than filling gaps with guessed inclusions.
Include every relevant line
- First-item and additional-item fees, including what counts as an extra pick.
- Packaging materials, inserts and custom preparation.
- Storage, receiving, returns, inspection and restocking.
- Monthly minimums and which fees count toward them.
- Technology, integration and account-management fees.
- Kitting, labeling and other special projects, including labor minimums.
- Billed postage, markup or label fees, carrier surcharges and later adjustments.
- Onboarding, peak charges and exit costs, shown separately where appropriate.
A headline-fee comparison can mislead
Illustration: for 1,000 one-item orders, Provider A charges $1.50 pick/pack plus $0.75 packaging: $2,250. Provider B charges $2 pick/pack including equivalent packaging: $2,000. B is $250 cheaper on those lines even though its pick fee is higher.
That is not yet a total-cost winner. Add identical storage, inbound and returns requirements, minimum shortfalls and actual billed postage before deciding.
Model those charges in the Fulfillment Cost Calculator. Its minimum applies to pick/pack and returns only; reconcile different contract eligibility separately.
Check the postage basis
Ask whether postage is billed from actual net carrier cost, a published rate card or another basis. Confirm which discounts and credits are passed through and how fuel, accessorial charges and post-shipment adjustments appear. Compare delivered service and packed dimensions, not just a claimed discount percentage.
Use 3PL shipping markups explained to ask clearer transparency questions.
Compare reliability alongside the total
Ask finalists to confirm inclusions and exclusions in writing. Weigh receiving turnaround, inventory visibility, error handling, communication, references and exit terms against the monthly cost. A proposal with unresolved assumptions is not directly comparable, even if its spreadsheet total looks lower.
For low-volume sensitivity, read 3PL monthly minimums explained.
For the broader decision, see How to choose a 3PL.