Yahoo! Auctions Japan Underpriced Deals — Below Sold Price

What it does: Works out what your keyword usually sells for on Yahoo! Auctions Japan (median of ended auctions with a bid), then returns live auctions at or below 80% of it.

You enter: keywords, e.g. Nikon Z6 (add a minimum price like ¥50,000 so accessories don't skew it); threshold

You get: per keyword: sold median (sold comps) and range, how many sold auctions it rests on, live listings checked, deal count and rate — up to 120 of each. Per deal (on by default): price now, buy-now price, bids, end time, discount, and whether it is payable today.

Price: $0.02 per keyword scanned (every keyword in your list is charged) + $0.002 per deal found; deals are on by default. A keyword whose sold prices are too few or too mixed is refused and not charged; a keyword with a usable median is charged even when it finds no deals.

Example: enter Nikon Z6 with a ¥50,000 floor → sold median ¥146,696 from 60 sold auctions · 28 deals among the 60 live listings checked · best 50.2% below the median (real run, 2026-08-09)

Unofficial — not affiliated with Yahoo! Auctions. Reads public pages only.

How the discount is worked out

1. Read ended auctions for the keyword — only ones that received a bid, because an ended auction with no bids is an asking price nobody accepted. Their median is the basis (up to 120 ended auctions, maxSoldComps).
2. Read the live listings (up to 120, maxLiveListings).
3. discountPct = (1 - price / soldMedian) x 100.
4. Return everything at or below your threshold (80% of the sold median by default), plus the price spread.

Two guards, because a basis can lie in two ways

Too few sold prices. minComps (default 8) refuses a keyword whose median rests on a handful of sales.

Too many kinds of thing. A camera search also returns its batteries, cases and manuals. maxCompSpread (default 4.0) compares the top and the bottom of the middle 50% range of the sold prices, and refuses a keyword whose two ends are more than 4x apart, pointing at the fix — an input like this:

{ "keywords": ["Nikon Z6"], "priceMinJpy": 50000 }

The price band is sent to Yahoo on both sides, so the sold prices and the live candidates cover the same tier.

In both cases the run returns basisUsable: false with the reason and that keyword is not charged. mixedKeywordLikely flags the remaining tell: in a coherent market only a small share of the live listings sits far under the median, so a high dealRatePct means the keyword is still mixed.

What comes back

One summary row per keyword, then (on by default) one row per deal. Real run, trimmed:

Measured on 2026-08-09 (real run) — { "keywords": ["Nikon Z6"], "priceMinJpy": 50000 }

{
  "type": "deal_summary",
  "keyword": "Nikon Z6",
  "basisUsable": true,
  "soldCompCount": 60,
  "soldListingsFound": 327,
  "soldMedianJpy": 146696,
  "soldPriceJpy": { "min": 69501, "p25": 99122, "median": 146696, "p75": 236250, "max": 294000, "average": 163864 },
  "liveListingCount": 60,
  "liveListingsFound": 90,
  "dealThresholdPct": 80,
  "dealCount": 28,
  "actionableDealCount": 28,
  "dealRatePct": 46.7,
  "mixedKeywordLikely": true,
  "bestDeal": {
    "type": "deal",
    "id": "l1237151687",
    "title": "Nikon Z6 ボディY267-Y3",
    "priceJpy": 73000,
    "buyNowPriceJpy": 73000,
    "bidCount": 0,
    "endTime": "2026-08-10T12:12:48+00:00",
    "discountPct": 50.2,
    "actionable": true,
    "priceIsFloor": false
  },
  "malformedCards": 0,
  "duplicateCardsDropped": 1,
  "checkedAt": "2026-08-09T17:31:41.046207+00:00"
}

actionable is the one to read: a running auction's price only goes up, so a discount against it is a discount against a floor. Only a buy-now price at or below the threshold can be paid today — dealCount is the honest superset, actionableDealCount the part worth acting on.

Page problems come back as numbers

The live search page is server-rendered HTML, not data, and it has sharp edges — cards that cannot be split on </li>, a listing shown twice per page, a total count that lives in the tab rather than in the <meta> description (which says approximately). malformedCards and duplicateCardsDropped ship with every summary, so a page redesign shows up as a number rather than as a quietly smaller sample.

Pricing

$0.02 per keyword scanned, plus $0.002 per individual deal returned (deals are on by default; turn them off with includeIndividualDeals). So one keyword that finds 28 deals costs $0.02 + 28 x $0.002, about 7.6 cents. You pay per keyword; there is no monthly fee. A keyword whose basis is unusable is never charged.

Read-only public pages, no login, throttled requests. The seller's name and id are never returned. Nothing is stored between runs.

If something goes wrong

• Wrong number or a failed run? Open a ticket on the Issues tab. I read every one and reply within 2 business days (Japan time).
• You never get a fake "empty" result. If the site can't be read, the run fails and says so.
• A keyword that can't be measured = no charge. Too few or too mixed sold prices and the keyword costs nothing. A keyword that could be measured costs $0.02 even when nothing is underpriced right now — that is the answer you asked for.
• Checked every week. An automatic test runs this tool weekly; if the site changes, I fix it.
• Public pages only. No login, no personal data, and it goes easy on the site.

More tools by the same author

• Yahoo! Auctions Japan Sold Prices — Median, Range, Bids
• Yahoo! Auctions Japan Listings — One Row Each, $0.0015
• Yahoo! Auctions Japan Price Trend — Sold Price by Month
• Mercari Japan Sold Prices — What Items Really Sell For
• Japan Used Camera & Lens — Dealer Price vs Sold Price
• Japan Figure & Gunpla — New Price vs Used Sold Price
• Used iPhone & Android Prices Japan — Dealer vs Sold
• Yahoo, Mercari & PayPay Japan — Same Item, 3 Prices

All tools (Japan marketplaces, real estate, jobs, racing, prediction markets): https://apify.com/jpmarketdata

Disclaimer

Unofficial, independent tool — not affiliated with, endorsed by, or sponsored by Yahoo! Auctions. Product names and logos belong to their owners and only say where the data comes from. Data is read from public pages, for market research; check before you act on it.