1818 with a potential die crack across the front of the coin

Your coin is probably worth $50-70. If you have a genuine die crack it's interesting but would not have a huge impact on value. However, what I see looks more like a deep scratch that would reduce value. Here's how you can tell which it might be: die cracks manifest themselves as RAISED on a coin, because when the die cracks, the metal from the planchet flows into the die from the coin. So look at the coin from an angle. I see two big stripes. One is a dark one passing her ear, the other, lighter, through her hair curl. Are they deep like a valley or gorge--indicating a scratch or planchet flaw--or are they raised like a ridgeline, suggesting a die crack? It's not the most beautiful coin, but the surfaces look original in color, which is preferable to being cleaned or altered.