Know what you have first
Before you talk to anyone, identify the coin: country, denomination, date, mint mark, metal and, if graded, the grade and certification number. Weigh it and photograph both sides. A seller who can describe the coin clearly gets better offers than one who walks in with a bag.
Do not clean the coins. Cleaning almost always lowers the price.
Pawn shops: fast, but built to lend or flip
A pawn shop offers a loan against your coin or buys it outright. In both cases it needs a margin, because it must resell, and it often has limited coin expertise. Offers are commonly based on metal weight for bullion-type coins and can sit well below collector value for anything rare.
A loan is not a sale: if you do not repay, you lose the coin, and interest and fees apply. Rules and costs vary by place, so read the agreement and ask for the total repayment amount in writing.
Coin dealers: a middle route
A dealer can value a coin quickly and pay on the spot. A dealer also needs a margin, so expect a bid below what the same coin would sell for to a collector. For common coins the gap is often small; for scarce or high-grade coins ask for several quotes.
A good dealer will explain the offer, and will not rush you. Be wary of anyone who pressures you to decide at once.
Auctions and marketplaces: best reach, more work
An auction exposes a coin to many collectors and can achieve the highest price for scarce items, but you pay a seller's commission, there may be photography or insurance fees, and payment can take weeks. A marketplace sale gives you control of the price but exposes you to returns disputes and fraud attempts.
Compare the net proceeds, not the headline price: sale price less fees, shipping and any time the coin sits unsold.
Use sold prices to judge any offer
Find the coin in the catalogue and read the sold results for the exact grade. The fair price tool shows the middle half of recent all-in sales in one currency. That range is what buyers have actually paid, including their premium.
Remember that a buyer's all-in price is not what you receive. A dealer buying from you typically offers below the range, and an auction seller receives the hammer price less commission. What matters is whether the offer is a sensible share of the evidence, and the answer will depend on how fast you need the money.
When the evidence is thin
If the tools say unavailable, there are fewer than five comparable recent sales. For a rare coin, get at least two independent opinions, ideally a grading service or a specialist auction house.
Never accept a figure that cannot be explained. If the buyer cannot say what comparable coins have sold for, assume the offer is low.