When you search a brand and model, the estimate is calculated from currently and recently listed instruments in our database that match your search, not from a fixed price book or manual valuation. The more comparable listings exist for a given model, the tighter and more reliable the estimated range tends to be; a model with very few comparable listings will show a wider range or, if there aren't enough matches at all, no estimate. Because it's based entirely on real listings rather than editorial opinion, the estimate reflects what sellers are actually asking right now, which can differ from what a buyer ultimately pays after negotiation.