Many factors go into the valuation of a coin.
Ultimately, the answer to what it's worth is really just what someone will pay for it. No quick answer. No definite answer at all really without seeing it. If you need resources to determine a coin's value, I recommend that you purchase two specific books which will arm you with the necessary tools to avoid selling at too low of a price. Next, I recommend you visit a local coin dealer to verify your thoughts on the market value.