I’m aware of kbb but I neglected to mention that I’m not in US so the car brands we are looking at will probably not the covered by kbb. I wanted to see if any

I’m aware of kbb but I neglected to mention that I’m not in US so the car brands we are looking at will probably not the covered by kbb. I wanted to see if anyone knows what goes into an entity like kbb saying that a certain used car is fairly priced at X. E.g., we looked at a year old used car with around 7500 miles on it. It was priced just 7% below the price of a identical new car. The first year depreciation curve of a new car says the sale price of a one year old used car should be 20% below new. I’m wondering if HN can help me figure out whether the dealer’s 13% (20%-7%) is reasonable or has some wiggle in it.