Well, buying and selling are the most obvious, but there are other things to consider like tax position. Are you an investor or are you a collector intending to sell? As an investor, you can write off losses on sales. Collectors cannot, but they can write off depreciation if the car is used for business. Both pay sales tax on purchases, and both pay a 28% tax on profit.

Auction prices dramatically affect values. Many appraisers only use auction prices which is a scary practice. You can easily end up paying additional sales tax on value that doesn't exist. Lowball sales can bury you in what you already own.

There's market value and market burden. When buying, be certain that the appraiser isn't relying on retail parts purchases or total labor costs to determine value, both can be subjective and labor costs are never 100% recoverable.

Knowing the ACV based on an average of auction results, dealer sales, private sales and most importantly, asking price and time on market. Vehicles from multiple grades should be included.  For example, Jaguars are known to fluctuate wildly.

A car can go from $100k to $30k in 6 months. Middle of the road is safe on these. The V-12 XKE in the photos was $70k "Restored" not appraised and all told cost $40k to repair and likely sold for $75k. The average is $90k, 36% below #1 high sale. Not an ideal investment. An accurate appraisal can save you from potential losses whether buying or selling.