Our Appraisal Methodology

At InstAppraisal, we believe accurate appraisals must be grounded in real market data — not guesswork. Here's exactly how we determine the value of your antiques, collectibles, and art.

The Three Pillars of Our Valuation

1. Comparable Sales Analysis

The foundation of any accurate appraisal is comparable sales — what similar items have actually sold for in real transactions. Our system maintains a database of 16,500+ verified sold prices from major online marketplaces, updated daily.

When you submit an item, we search for the most relevant comparables based on:

• Object type matching — a Victorian rocking chair is compared to other Victorian rocking chairs, not modern office chairs
• Material compatibility — porcelain vases are compared to porcelain, not glass
• Maker/brand matching — a Rolex is compared to other Rolex watches, not generic timepieces
• Era and period — items are compared to pieces from the same approximate time period
• Condition alignment — working items aren't compared to broken or parts-only listings

Our quality scoring system evaluates each comparable on 8 dimensions: category, object type, material, maker, period, size, completeness, and market relevance. Only comps that score above our quality threshold are used for pricing.

2. Historical Appraisal Intelligence

Since 1999, InstAppraisal has built an archive of 85,000+ appraisals across every major collecting category. This gives us something no competitor can replicate: decades of real-world pricing patterns.

Our historical data provides:

• Category baselines — statistical medians and ranges for 34 categories and 25 subcategories
• Maker premiums — data-driven multipliers for recognized brands and makers
• Condition impact — how condition grades affect value across different categories
• Trend detection — which categories are appreciating and which are softening

3. Expert Appraiser Knowledge

Our database includes 6,200+ valuations from certified appraisers and industry professionals. These expert assessments serve as authoritative reference points, especially for:

• Items where comparable sales are limited
• Categories where specialist knowledge significantly affects valuation
• Items with authentication or attribution questions

Understanding Fair Market Value

Our appraisals estimate fair market value (FMV) — defined as the price at which property would change hands between a willing buyer and a willing seller, neither being under compulsion, and both having reasonable knowledge of the relevant facts.

In practical terms, FMV represents what an item would sell for:

• At a well-attended auction
• In a private sale between knowledgeable parties
• Through a reputable online marketplace

How FMV Differs From Other Values

Value Type	Relative to FMV	When Used
Fair Market Value	Baseline	Estate planning, general knowledge
Insurance/Replacement	1.5-3x higher	Insurance policies, claims
Dealer Retail	2-4x higher	What dealers charge in shops
Liquidation	0.3-0.5x lower	Quick sale, estate cleanout
Auction Estimate	~FMV	Auction house pre-sale estimates

Our Quality Controls

Comp Eligibility Gate

Before any comparable sale enters our pricing calculation, it must pass our eligibility gate. This automatically rejects:

• Parts, accessories, and incomplete items
• Reproductions and replicas
• Miniatures and toys mistaken for full-size items
• Modern retail items (Walmart, IKEA, Target brands)
• Broken or non-functional items (unless the target is also)
• Lots and bundles (unless the target is also a lot)

Trustworthiness Classification

Our system classifies each valuation into confidence tiers:

• Trustworthy — strong comparable evidence supports the estimate
• Partial — some evidence exists but with gaps
• Abstain — insufficient evidence to provide a reliable estimate

We'd rather tell you we don't have enough data than give you a misleading number.

Material-Aware Floors

For items with intrinsic material value (gold jewelry, sterling silver, platinum), our system enforces minimum value floors based on material content. A 14K gold ring will never be valued below the gold content floor, regardless of other factors.

Continuous Improvement

Our system improves every day through:

• Daily data updates — fresh comparable sales and new appraisals
• Weekly baseline recalibration — statistical models rebuilt with latest data
• User feedback integration — "value too low" and "value too high" signals inform tuning
• Expert review loop — professional appraisers validate and improve AI estimates

When to Seek a Professional Appraisal

Our AI appraisals are excellent for general valuation knowledge and market awareness. However, we recommend professional human review for:

• Items valued over $5,000
• Insurance documentation
• Estate settlement and tax purposes
• Legal proceedings
• Items requiring authentication

InstAppraisal offers professional Human Review as an upgrade to our AI appraisals.

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