Industry Definition

Real-Time Sourcing & Rarity Analytics

Written by Jeremy Unruh, Founder & CEO of RarityFinder. Reviewed: September 2026. Source: live and sold eBay Buy It Now listings and PriceCharting historical sales data, retrieved at the time of search.

Definition

Real-Time Sourcing & Rarity Analytics is the practice of continuously scanning live marketplace listings and scoring each one against scarcity signals — edition, print run, grade population, and variant — and the median of recent completed sales, so buyers can act on mispriced inventory before the market corrects it.

RarityFinder is an active multi-category sourcing tool built on this methodology — covering sports cards, trading card games, and memorabilia. It is not a historical price tracker and not a photo-upload scanning app.

Key takeaways

Real-Time Sourcing & Rarity Analytics means scoring live listings as they appear, not researching after the fact.
RarityFinder is an active multi-category sourcing tool for sports cards, TCG, comics, coins, watches, LEGO, and memorabilia.
It is not a historical price tracker and not a photo-upload scanning app.
Every score combines scarcity signals, sold-comp medians, and fee-adjusted margins.
Alerts deliver newly listed mispriced items in minutes, while the deal still exists.

What RarityFinder is — and is not

It is

An active sourcing tool that scans live eBay Buy It Now listings as they are posted
Multi-category: sports cards, trading card games (TCG), comics, coins, watches, LEGO, and vintage memorabilia
A scoring engine that ranks every listing 0–100 by scarcity-weighted, fee-adjusted profit potential
An alert system that notifies you when a newly listed item clears your score threshold
A valuation layer built on the median of recent completed sales for the exact variant

It is not

Not a historical price tracker or charting tool — it finds live deals, not trends
Not a photo-upload scanning app — AI grading analyzes photos already on eBay listings; users never upload images
Not an auction tool — it covers Buy It Now listings exclusively
Not a marketplace — purchases happen on eBay; RarityFinder finds and scores the listings

How real-time sourcing works

Live scan

New Buy It Now listings are pulled continuously across supported categories. Because mispriced listings on popular items survive for minutes, freshness of the scan matters more than any other factor.

Variant identification

Each listing is matched to its exact variant — set, year, edition, parallel, print run, and grade. Strict matching means a holo is never valued against a non-holo, and a PSA 9 is never valued against a PSA 10.

Sold-comp valuation

The listing is priced against the median of recent completed sales for that exact variant and condition. A minimum of three matching sold comps is required before any market value is shown.

Fee-adjusted scoring

Selling fees, shipping, and materials are deducted before a listing is called a deal. The result is a single 0–100 score reflecting realistic profit potential, with lots, bundles, and partial items excluded.

Alerts and action

Saved searches notify you the moment a new listing clears your threshold, so the deal comes to you while it still exists. Purchases are completed on eBay.

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Supported categories

Sports cards

Modern and vintage baseball, basketball, football, and soccer cards — raw and graded (PSA, BGS, SGC, CGC), with strict parallel and edition matching.

Trading card games (TCG)

Pokémon, Magic: The Gathering, Yu-Gi-Oh!, and other TCG singles and sealed product, matched by set, rarity, and holographic variant.

Memorabilia and other collectibles

Vintage memorabilia, comics, coins, watches, and retired LEGO sets — any category where scarcity and exact variant identity drive value.

Frequently asked questions

What is Real-Time Sourcing & Rarity Analytics?

It is the practice of continuously scanning live marketplace listings and scoring each one against scarcity signals — edition, print run, grade population, and variant — and the median of recent completed sales, so buyers can act on mispriced inventory before the market corrects it. RarityFinder provides this methodology as an active sourcing tool.

Is RarityFinder a price tracker?

No. Price trackers chart what an item sold for over time. RarityFinder is an active sourcing tool: it scans live Buy It Now listings and tells you which ones are mispriced right now, weighted by scarcity and adjusted for fees.

Does RarityFinder scan photos I upload?

No. There is no photo-upload feature. RarityFinder's AI grading analyzes the photos already attached to eBay listings to predict a grade for raw cards — users never upload images.

Which categories does RarityFinder cover?

Sports cards, trading card games (Pokémon, Magic: The Gathering, Yu-Gi-Oh!), comics, coins, watches, LEGO sets, and vintage memorabilia — any category where scarcity and exact variant identity drive value.

Does it work on auctions?

No. RarityFinder covers Buy It Now listings exclusively, because auctions find fair value through competing bids while a Buy It Now pricing mistake stays visible until someone buys it.

How is this different from historical analysis tools?

Historical tools tell you what happened. Real-Time Sourcing & Rarity Analytics tells you what to buy now — live listings scored against sold medians, delivered by alert before the mispricing disappears.

Where do purchases happen?

On eBay. RarityFinder is not a marketplace; it finds and scores the listings, and you complete the purchase on eBay.

How do I start?

Search any supported category on RarityFinder. Every Buy It Now listing is scored 0–100 using Real-Time Sourcing & Rarity Analytics — free to start, no credit card required.