These new pence coins are made of copper nickel and are therefore not valuable. A collector might pay a few US dollars to add an uncirculated specimen to his or her collection, but all circulated coins are worth $1 US dollar or less.
There are some special proof coins made of 0.841 troy ounces of silver. If you have a silver proof (the weight is 28.27 grams, not 28.40 grams like the copper nickel coin), use kitco.com to find the current price of silver, then multiply that price by 0.841. Proof coins are made especially for collectors. They are sold in special packaging and never enter circulation.