Price is the first thing buyers check and the last thing they should trust alone. Counterfeit sellers need to undercut legitimate sellers enough to win the buy box or the click, but not so much that the listing screams fake. That tension creates patterns. Legitimate discounts have reasons (clearance, refurbished, gray-market import, seller error). Counterfeit discounts have a different shape: persistent, uniform, and oddly resistant to the normal noise of retail pricing.
The classic tell is a price far below every other seller with no plausible explanation. A current-model product at 40 to 60 percent off from an unknown seller, while authorized retailers hold at full price, is the textbook counterfeit listing. Legitimate deep discounts happen, but they come with context: end-of-life clearance from a known retailer, manufacturer-refurbished units labeled as such, or open-box items with the condition stated. A steep discount with no story is a story in itself.
Calibrate by category. Luxury goods almost never discount deeply through legitimate channels, so any significant markdown is suspicious. Electronics have real variance (sales, bundles, older revisions), so the anomaly threshold is higher. The question is never "is this cheap" but "is this cheap relative to what legitimate sellers charge for exactly this item right now."
The subtler signal is a price that never moves. Legitimate marketplace sellers adjust prices constantly: responding to competitors, clearing inventory, reacting to demand. Counterfeit operations often price once and leave it, because their margin is built into the fake's production cost and they are optimizing for volume, not for the market. A listing that holds the exact same price for months while comparable listings fluctuate is worth a closer look at the other signals.
Related: the uniform discount across a whole catalog. A seller offering every product at exactly 30 percent off is not running a sale; they are running a pricing formula. Legitimate sellers discount selectively. Formula pricing across unrelated products suggests the seller's cost basis is uniform, which is exactly what you would expect from someone sourcing fakes.
Price anomalies are triage, not proof. A gray-market importer can legitimately undercut by 20 percent. A seller clearing last year's model can go deeper. The way to separate them is convergence: does the pricing anomaly arrive with other signals (new seller account, stock photos only, ships-from mismatch, review patterns that do not fit)? One anomaly is a deal worth verifying. Three is a listing worth avoiding.
When you do buy at a discount, the verification is the same regardless: check the product against the brand's authentication guidance the moment it arrives, and keep the listing screenshots. If it is fake, the pricing anomaly documented at purchase time is what makes the marketplace claim straightforward. The discount told you where to look; the product tells you what you found.