I`v found some ancient coins (B.C.) could you give me some reference for knowing the price??

Treasure Trove is a British thing and does not exist in the U.S. or a lot of other countries. As was said, if the coin has the letters B.C., as well as a date on it, then it is a fantasy item. No one knew during the BC period Christ was going to show up and a new dating system would be started. Without seeing the coin no one here can help you. Take it to a coin dealer that deals in ancients. Sorry this is the best I can do with the info you gave.

I`v found some ancient coins (B.C.) could you give me some reference for knowing the price??
If you have dug them up out of your garden - you must take them to either your local county archive department or the police. They might be 'treasure trove' and might belong to the state rather than you. Take some photos in the meantime and send them to the Keeper of the Department of Coins and Medals, British Museum, London, WC1. He or she would be able to help you date them and will tell you if they are common or unusual.
Reply:How do you know they are "B.C." If that's stamped on them then they are fake.