The following is excerpted from Clifford Mishler’s Coins: Questions & Answers:
Is it time to sell your coins? Perhaps you don’t consider yourself a collector, but you’ve inherited a cigar box full of Grandpa’s old pocket change. Or maybe you’ve spent years in the hobby, and you feel like it’s time to explore new paths. You might be drawn to a different collecting speciality within numismatics, or even to a completely new hobby. Perhaps your life circumstances have changed, and you need to cash in (however reluctantly) on your investment. Or maybe you want to take advantage of the current “hot” coin market by selling off some of your collection’s duplicates.
Regardless of why you’re selling, you now have some decisions to make. Will you sell your collection privately, to a local coin dealer? Shop it around to dealers nationwide? Consign it at a public auction? Or maybe auction it yourself, on the Internet? What are the benefits of each path, and which will bring the greatest profits?
To get started, the first question you should answer is, “What kind of collection do I have?”
Rolls of modern Coins, Proof sets, modern commemoratives, bullion, etc. This includes bulk investment coins, such as American Eagle bullion pieces, bags of common circulated silver coins, rolls of Uncirculated statehood quarters, and so on. It also includes modern commemoratives and Proof and Uncirculated sets from the U.S. Mint, not all of which have increased in value in the secondary market. Such coins and accumulations are best sold privately to a coin dealer or to another collector. Auctioning them yourself, on the Internet, is also a potential route. Consigning them to an auction house is not likely to be your best option, as this venue is typically reserved for scarcer coins.
Coins with sentimental—but not necessarily high-dollar—value. You might have inherited or gathered an accumulation (as opposed to a studiously compiled collection) of coins—for example, a coffee can full of Wheat cents, or a jar full of Buffalo nickels pulled years ago from pocket change. Your local coin dealer can make you an offer on such coins, either buying the entire lot or searching through them to “cherry pick” the better pieces. If you have the time and inclination, you might sell them yourself, through an Internet auction site. The same advice applies to individual lower-value coins, tokens, and medals. Additionally, you might consider donating such coins to a local Boy Scout troop or similar organization (this encourages coin collecting as a hobby, and may be tax-deductible).
Rare and/or significant coins. For rare, valuable, and historically significant coins, a public consigned auction is often the best way to sell, potentially bringing much higher prices than you could get selling to a dealer. Dedicated collectors subscribe to auction firm catalogs, knowing they are good sources for scarce and expensive coins. When you consign your collection to a well-established auction house with numismatic experience, your coins will be carefully studied, cataloged, publicized, and presented to an audience of serious collectors with money to spend. You save the time and effort of searching for potential buyers, perhaps traveling, worrying about security, etc. The auction firm makes money by collecting a commission on each sale.
Another option for selling your rare and significant coins is to approach a dealer nationally recognized as an expert in the field—for example, a specialist in 18th-century gold, or a dealer who focuses on colonial coins.
You can also receive tax benefits from donating your rare or significant coins to the American Numismatic Association, the American Numismatic Society, or a museum.
After you’ve considered the scope of your collection, you can decide the best venue for selling.
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