How to Value Collectibles for Your Net Worth: Watches, Art and Coins Without Fooling Yourself
7 min read
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7 min read
You have a watch, a painting or a box of old coins. Someone once told you it was worth Rp120 million. So that is what you wrote in your net worth.
But if you had to sell it next month, would you get Rp120 million? Almost surely not.
This post shows how to value collectibles for your net worth in a way you can defend to yourself. It uses one simple tool: a haircut. A haircut means you cut the number down on purpose, to allow for the costs and delays of selling. The worked example is NetWort arithmetic with made-up figures. The facts about valuation terms come from the sources linked below, checked on 22 October 2026.
The first trap is that "value" is not one number. It is at least three.
Chubb, an insurer that covers fine art and collectibles, explains the difference like this:
The gap can be big. One appraisal guide gives an example of a family ring valued at $12,000 for insurance that then sold for only $5,800 (Appraisily). It is one example, not an average. But it shows why a paper from your insurer is not a sale price.
The US tax authority says the same thing in its own words. Its guide on valuing donated property says fair market value is not the figure an appraiser set so that your insurer would reimburse you (IRS Publication 561).
If your only number is an insurance paper, you hold the highest number, not the likeliest one.
Why does the sale price come in lower? Three reasons.
1. Selling costs money. At an auction, the seller often pays a commission. One art-market guide says sellers typically pay about 15% of the hammer price, plus fees for things like insurance and cataloguing. For big consignments it can be negotiated down or waived (MyArtBroker). Fees differ by house and item, so treat 15% as a planning figure and not a quote.
2. Dealers need a margin. A dealer who buys from you must resell. So the dealer offers less than the price they hope to get.
3. Time is a cost. The right buyer may take months. If you need cash sooner, you accept less. Our post on why collectibles are less liquid than they look walks through real round-trip numbers for watches.
None of this means your collectible is a bad asset. It means the number on paper and the number in your bank account are different, and your net worth should lean towards the second one.
Here is a four-step way to turn a hopeful number into an honest one.
Now a worked example. This is illustrative arithmetic, not market data.
Say you own a watch you bought for Rp80 juta. Your insurance paper says Rp120 juta. A similar watch in similar condition recently sold for Rp95 juta.
| Step | Figure |
|---|---|
| Insurance appraisal (replacement value) | Rp120.000.000 |
| Recent comparable sale | Rp95.000.000 |
| Less 15% selling costs | Rp14.250.000 |
| Estimated net if sold | Rp80.750.000 |
| Number you log (rounded down) | Rp80.000.000 |
The gap between the paper value and the logged number is Rp40 juta, or about 33% of the insurance figure. Your net worth is Rp40 juta lower than if you had used the insurance paper. That is the point. It is better to be pleasantly surprised at sale than shocked.
The haircut idea works for all three, but the details differ.
Watches are the easiest to check, because the same model is sold again and again. Sold-price records for your exact reference are the best evidence you can get. Condition, box and papers matter.
Art is harder. Each piece is one of a kind, so there may be no truly matching sale. Auction results for the same artist and a similar size and period are the closest thing. Expect wider error bars, so a bigger haircut is reasonable.
Coins have two prices. One is the metal value, which you can look up. The other is the collector premium, which depends on rarity and condition. Our post on coin value as a collector versus as metal explains the split. A safe habit is to log the metal value as a floor and treat any extra as unconfirmed until you see a real sale.
Collectibles cannot be priced from a live feed, so you enter them by hand as a manual asset.
Open Holdings and choose Add Manual Asset. Pick the Luxury Goods category. It has two sub-categories: Collectible (the example it names is a Rolex), which defaults to +5% a year, and Standard, which defaults to -15% a year. You can change the annual rate.
NetWort grows or shrinks a manual asset at the rate you enter, compounded daily. It does not look up a market price. So one honest way to use the form is:
This resets your starting point to a number you believe. It does mean the asset shows no gain or loss against what you originally paid. If you want to keep your original cost, enter the original price and date instead, and set the rate so the value today matches your haircut number. Then revisit it once a year.
A last point. Our post on why manually tracked assets are often out of date explains what happens when you set a rate and forget it. Put a yearly reminder to check recent sold prices.
Valuing is only half of it. Also check whether your home policy covers these items at all: see how to insure valuables like watches, jewellery and art.
Open Holdings and look at the collectibles you have logged. For each one, ask: is this number a sold price after costs, or an old appraisal? If it is the appraisal, replace it with your haircut number and see how your net worth changes.