The value of your coins depends on their condition, country of origin, mintmarks (if any), what type of errors they are, etc. Error coins from the US are generally valued from hundreds to thousands of dollars at a minimum. I suggest that you bring your coins only to a certified coin dealer to be sold. Since I can't see exactly what type of errors you have I can't appraise them. Whatever you do DO NOT clean them or they will become worthless!!! I do not suggest selling them online unless you get them graded by either PCGS, ANACS, or NGC (that tends to be expensive and a pain for people who don't know much about coins). So unless you get them graded, I would only sell them to a coin dealer or you won't get but a fraction of their value.