How Deal Scoring Works in Collect Detect
Every time you view a graded card listing on eBay, Collect Detect runs a deal score in the background. It combines verified cert data, real-time sold comps, and population report scarcity into a single verdict: Buy, Watch, or Pass. Here's exactly how it works.
Signal 1: Price vs. Market
The core of the deal score is the gap between the listing price and the trailing 90-day eBay sold average for the same card, grade, and grader. We weight recent sales more heavily than older ones — a card that sold for $80 three months ago and $110 last week is trending up, not averaging at $95.
A listing priced 20%+ below the weighted average starts scoring positively. The further below market, the stronger the buy signal — but only after the other two signals are checked.
Signal 2: Cert Verification
A below-market price means nothing if the cert is invalid, swapped, or the grade doesn't match. Before the deal score is shown, Collect Detect verifies the cert number against the grading company's registry. An unverified cert immediately produces a Pass verdict, regardless of price.
"Price alone is not a deal. A verified cert at a below-market price is a deal."
Signal 3: Population Scarcity
Pop reports tell you how many copies exist at this grade. A PSA 10 with a pop of 2 on a card with 500 PSA 9s is meaningfully scarcer than a PSA 10 with a pop of 400. Scarcity amplifies the buy signal — a card that's both below market and genuinely rare scores higher than one that's just cheap.
The Scoring Formula
| Factor | Weight | Direction |
|---|---|---|
| Price vs. 90d avg | 50% | Lower = better score |
| Cert validity | Gate | Invalid = instant Pass |
| Pop scarcity | 30% | Lower pop = better score |
| Price trend (30d) | 20% | Rising market = better |
What the Verdicts Mean
- Buy — cert verified, priced below market, pop supports the premium
- Watch — cert verified, price is fair but not exceptional — worth monitoring
- Pass — cert invalid, overpriced, or pop is too deep to justify the ask
Deal scoring isn't about finding cheap cards. It's about finding cards where the math — price, verification, and scarcity — all point in the same direction at once.