Just determine the value of a single coin or collection; you need to make sure you are in good hands. Take your time for someone to rate them, or they might take advantage of you. Instead, you need to know what to look for from an experienced coin collector.
Try reaching out to three different people to get an idea of what they are worth.
If you find that the estimates vary widely, you might ask why. Several such experts collect coins that will estimate their value for free. Others have fees they expect from you. This is because you have decided to keep your coins, sell them, or disagree with their value. This way, you can get an excellent overall deal. Sometimes an experienced coin collector will offer a lower price hoping that you will decide to sell the coins. They can then add these coins to their collection and get a higher value than they paid for. They can also sell these coins to someone else and make a profit at your expense.
Ask them about their coin collection, how long they have been in the field, and what they like best about it. As these conversations go on, you can get a good idea of the experiences and ideas that the person has to offer in terms of coin pricing. You will find that talking to an experienced coin identifier by photo can be very interesting, so take your time. Also, find out if you need to make an appointment. They can also answer some of the questions coin collectors might have.
Many of these experts are self-taught and can support your experience. Some of them still do things the old fashioned way. However, many of them now rely on software and the Internet to determine the correct value for the coins they see. They can learn about faulty coins, rare and widespread coins.