Local-first secondhand offer calculator

Lowball Lab

Know your fair offer, lowball, walk-away price, profit, and ROI in under 30 seconds before you message.

Join early access Try the math Newman AI Works

30-second offer range Walk-away ceiling Profit and ROI at ask No marketplace login

Listing Used mirrorless camera kit Asking $420

Fair$332

Lowball$239

Walk$361

ROI31%

COUNTER

Preview the workflow

Fast deal math before you offer.

Enter the ask, resale value, and real costs. Lowball Lab turns that into a fair offer, lowball, walk-away price, profit, ROI, and a clear verdict.

01 Listing Paste or type the ask and condition notes.

02 Costs Add fees, repairs, shipping, pickup, and risk.

03 Verdict See buy, pass, counter, or lowball instantly.

Electronics Games Anime figures Collectibles Tools Furniture

Verdict COUNTER

Offer below ask and keep the walk-away tight.

Fair offer$0

Lowball$0

Walk-away$0

Profit at ask$0

ROI at ask0%

Total friction$0

Why it exists

The asking price is only one piece of the deal.

Lowball Lab is for the quick moment before you send an offer. It helps you avoid fake-profit deals by forcing the real costs into the math: platform fees, repairs, shipping, pickup time, uncertainty, and the margin you actually want.

The draw is speed. Instead of doing rough mental math in a parking lot or message thread, you get a fair offer, lowball offer, walk-away ceiling, profit read, ROI, and a clear buy/pass/counter verdict.

How the numbers work

Lowball Lab turns a listing into a range.

The app does not guess the value for you. You enter or paste the listing details, then it uses your expected resale number and deal costs to calculate the offer ceiling.

Start with resale

Expected resale is the top line. This can come from your own comps, marketplace checks, sold listings, or category presets.

Subtract friction

Fees, repairs, parts, shipping, pickup time, and a risk buffer get pulled out before the app recommends an offer.

Protect margin

Your target margin becomes the guardrail. The walk-away price is where the deal stops being worth chasing.

Walk-away price = resale - costs - risk buffer - target profit

Fair reasonable opener Lowball aggressive opener Walk-away max price Profit and ROI if you pay ask

What it does

Built around the moment before you message.

Paste or type

Keep listing details, asking price, and condition notes in one quick calculation without a marketplace login.

Add real costs

Include repairs, shipping, travel, marketplace fees, and risk so the deal is not fake-profitable.

Get offer ranges

See fair offer, lowball offer, walk-away price, expected profit, and ROI.

Decide fast

Use the buy, pass, counter, or lowball verdict before spending time negotiating.

Free vs Pro

Planned Pro tools for buyers who run more deals.

Free stays fast for quick manual checks. Pro is for repeat buyers who want less typing, clearer deal breakdowns, saved ranges, and category tuning without turning the app into a heavy platform.

FreeManual calculator, offer range, walk-away, profit, ROI, and verdict.

ProPaste-link helper, deal breakdown, saved ranges, and category presets.

Paste-link helperPlanned for Pro: paste a Marketplace, eBay, Mercari, or local listing link. When available, Lowball Lab pulls title, ask, condition, and shipping notes, then you confirm the numbers.

Deal breakdownShow what kills margin and what price makes the deal worth it: fees, repairs, risk, pickup cost, resale spread, and walk-away pressure.

Deal memorySave the last calculations and keep offer ranges handy while messaging sellers.

Category presetsTune risk for electronics, games, tools, furniture, collectibles, and anime figures with box/no-box, authenticity, fragile shipping, and sold-comp spread notes.

Built for

People who need the math before the meetup.

Marketplace buyersLocal pickup, online listings, and quick resell checks.

FlippersElectronics, games, anime figures, collectibles, tools, furniture, and niche finds where condition and sold-comp spread matter.

Deal huntersAnyone who wants a clear offer ceiling instead of guessing under pressure.

Coming soon

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Join for launch updates, early access notes, and product feedback asks. This list is only for Lowball Lab.