Offer calculator for secondhand buys

Know the math before you make the offer.

Type what the seller asks and what it is worth. Get the offer to make, where to open, and when to walk away.

Google Play App Store Try the worksheet

Live on iPhone and Android
No account
Buy, counter, lowball or pass

Lowball Lab offer screen for a Coach leather tote: offer $83, open at $76, walk away $90

Offer worksheet

Your numbers. Your plan.

Change any number and the offer moves with it. You enter the values; nothing is pulled from a price feed.

Suggested call COUNTER

Offer below ask and keep the walk-away tight.

Offer$0 $0Open at $0Walk away

Profit at ask: $0
ROI at ask: 0%
Total costs: $0

Illustrative planning math only. Verify value, condition, authenticity, fees, and safety before buying.

Free and Pro

What it does.

Free covers the offer. Pro adds the tools for buying often. Your deals stay on your phone either way.

Offer math

The offer, where to open, where to walk away, profit and a clear call.

Free

Pickup checks

Risk prompts and item checks before you hand over cash.

Free + Pro

Compare prices

Search sold and retail prices from the item title when you choose to.

Pro

Saved deals

Keep notes, offer ranges and pickup proof on your phone.

Pro

Private by default

No app account, no Newman cloud for deal data, no analytics SDK.

Always

Lowball Lab Pro

Pay how you buy.

The app is free. Pro is bought through Apple or Google, and the store shows your local price before you pay.

7-day trial

Monthly

$2.99 per month

Flexible access for active deal runs.

7-day trial

Annual

$14.99 per year

The lower-cost subscription path for regular buyers.

No trial

Lifetime

$29.99 one time

One purchase for the lifetime Pro entitlement.

Monthly and Annual include a seven-day trial where offered. Lifetime is a one-time purchase and does not include a trial.

Google Play App Store

Fast answers

The deal math in plain terms.

Use caseWhat is Lowball Lab for?

Lowball Lab helps secondhand buyers check a seller ask against resale value, costs, risk, target margin, profit, ROI, and a buy, pass, counter, or lowball verdict before messaging.

StatusIs Lowball Lab live?

Lowball Lab is live on the App Store for iOS and on Google Play for Android.

PrivacyDoes Lowball Lab scrape marketplaces or require a login?

No. Lowball Lab is built around local calculation and user-confirmed comp checks. It does not promise marketplace scraping or require a marketplace login.

OutputWhat numbers does the calculator show?

The worksheet shows the offer to make, where to open, where to walk away, profit at ask, ROI at ask, total costs, and a simple call for the deal.

Field notes

Keep the decision useful.

Offer-math checklistRun the full cost and margin check. Comp-check workflowConfirm a value without pretending it is automatic. Lowball updatesPublic release notes and product changes.