Article in English: Unscrupulous buyers give low offers in the hopes of getting a better deal. Watch the person evaluate your coins, if possible. They should analyze each coin individually. Avoid anyone who offers you a flat price without bothering to take a long look at the coins. Say no to any buyer who pressures you into selling coins immediately. Look for dealers with positive reviews and accreditation from well-known numismatics organizations. Shop around to get the most from your coins. Let multiple dealers evaluate their coins and make offers on them. Tell each one that you’ll “think about their offer and come back later.” Then, when you’re ready to sell, choose the dealer that you feel comfortable doing business with. When selling a plentiful collection of coins, it’s better to keep the coins as a package deal. Many dealers will be interested in only a few coins. They’ll pick out the high-value coins, leaving you with a less valuable collection that’s harder to sell. Set a price for the total collection and stick to it. Even a coin you got for free can cause you legal problems. Your government likely taxes any profit you make off of sold coins. That’s why it’s important to keep a detailed list of every sale you make as well as any coin purchases. Consult your local tax laws to find out how to report your income.

Summary in Indonesian:
Pilihlah pembeli yang memberikan analisis yang adil. Biarkan koin dievaluasi oleh banyak pembeli. Jual koleksi Anda secara grosir. Catatlah semua penjualan Anda.