Valuation
Hagerty Price Guide vs. Bring a Trailer: How To Read Both
When we underwrite a car for acquisition, we look at two primary data sources: the Hagerty Price Guide and recent Bring a Trailer comparable sales. They agree most of the time. When they disagree, we usually trust BaT. Here is why, and how a private seller can use both to triangulate a fair number.
What Hagerty Price Guide is
Hagerty publishes value estimates for collector cars across four condition tiers (Concours, Excellent, Good, Fair). The data sources include insurance claims and policy values, registered Hagerty appraisals, and auction sale prices the Hagerty data team manually curates. The result is a smooth, stable, conservative estimate of what a typical car of that year, model, and condition is worth.
Strengths: comprehensive coverage across decades and models, condition-tier granularity, stable enough to be useful for insurance valuations and financial planning.
Weaknesses: lags the market by 3 to 9 months on appreciating cars, smooths over outlier transactions that may be more representative of where the market is heading, does not capture the premium for documentation, color, original ownership, and provenance.
What Bring a Trailer comparables are
Bring a Trailer is the dominant online auction platform for enthusiast cars. Each car listed includes detailed photographs, documentation, ownership history, and bid history. Sold listings are public and searchable.
Strengths: real-time market data, full transaction transparency, broad model coverage including modern halo cars and recent classics, the closing prices include the buyer's premium so you can see the actual money that exchanged hands.
Weaknesses: not every car is right for BaT, the audience is heavily skewed toward documented enthusiast condition, no-reserve auctions skew the bottom of the distribution downward, modified cars with unique builds are hard to compare against a clean reference set.
How we reconcile the two
Our process is straightforward. We pull the Hagerty value for the year and condition tier as our baseline. We then pull the most recent 5 to 10 BaT sales of the same model, similar year, similar mileage. We compute the median sale price and compare it to the Hagerty Excellent or Concours value depending on the BaT cars' condition.
When BaT is within 10 percent of Hagerty, we use Hagerty as the baseline and adjust for specific car features. When BaT is meaningfully above Hagerty, we lean toward BaT because it represents what buyers are actually paying right now. When BaT is meaningfully below Hagerty, we look for explanations (recent oversupply, a specific year with known issues, broader market softness).
What sellers should pull before getting offers
Before requesting an offer (from us or anyone else), pull this:
- Your Hagerty Price Guide value at Excellent and Concours condition tiers
- The last 5 sold BaT listings for your year/model, with sale prices and links
- Photos of your car's strongest features (originality, documentation, low mileage, rare options)
Show this to any buyer. A buyer who is interested in giving you a fair price will be glad you did the work; a buyer who is hoping to underprice the car will get visibly uncomfortable. That information asymmetry alone is worth several thousand dollars on a six-figure car.
Where we fit
Our offers come in 8 to 18 percent below the reconciled retail number, with the spread reflecting our acquisition margin and resale-channel risk. We will share the specific Hagerty value and BaT comparables we used to arrive at your offer. If you would rather take your car to BaT directly and wait 8 to 12 weeks, we will tell you whether we think you will net more that way (sometimes you will, especially with documented Concours-grade cars).
Submit your car and we will walk through the valuation with you.