Lowball Lab

A Secondhand Offer Math Checklist

4 min readLowball LabNewman AI Works

A good secondhand offer is not just a lower number. It is a quick sanity check on comps, costs, risk, and whether the deal still makes sense if the seller says yes.

THE SHORT VERSION

Three takeaways.

Keep the useful core visible and under the user's control.

01 Check sold comps before anchoring.
02 Subtract fees, repair risk, and pickup friction.
03 Write the walk-away number before negotiating.
01

Start with sold comps

Asking prices are useful context, but sold comps are the anchor. A quick offer check should separate what sellers want from what buyers actually paid, then adjust for condition, bundles, missing parts, and local demand.

Check sold comps before anchoring.
02

Price the friction

A cheap item can become expensive once pickup time, platform fees, shipping, repair parts, cleaning, storage, and relisting effort are included. The offer should leave room for those costs before profit is counted.

Subtract fees, repair risk, and pickup friction.
03

Set the walk-away number

The walk-away price protects the buyer from negotiating against themselves. If the offer only works when every assumption goes right, passing is often the cleanest decision.

Write the walk-away number before negotiating.
Check sold comps before anchoring.

A good secondhand offer is not just a lower number. It is a quick sanity check on comps, costs, risk, and whether the deal still makes sense if the seller says yes.