Looks like a genuine Chinese cash coin of around the 18th century to me. The two characters in your first image would be the name of the mint. Without quick reference handy, I will defer to those more knowledgeable about Chinese coins. Your example looks a bit rough but that's not unusual. Generally speaking, Chinese cash of that era are extremely common and I've paid as little as 25-50 cents for pieces that look like that. However, there are better varieties out here that might be worthwhile. Again, I will defer to the specialists on that.
Your ID is correct, it's the Xianfeng Emperor (1851-1861), mintmark looks like Board of Works (one of the two most common) but I sometimes have trouble with the mint marks. The reign of Xianfeng was a very troubled time in Chinese history, with the Taiping Rebellion causing economic trouble that affected the coinage, including the casting of many large multiple-cash coins. The roughness may be due to an official mint experiencing production troubles, or possibly an "unofficial" mint filling in for a shortage of circulating money. Either way, the value would be about the same (i.e. not very high, maybe a dollar or so) for such rough piece. Still, an interesting historical relic from a fascinating time in history- I recommend reading up on the Taiping Rebellion if you aren't already familiar with it.
@Kevin wu : What specifically do you think looks fake about the OP coin? The OP inscription is correct for an ordinary tong bao coin (the photo you attached shows a yuan bao) and the roughness of casting could be either a poor product of an official mint, or a contemporary unofficial coin. (I guess an "unofficial" contemporary coin would technically be a fake, but if it circulated at the time it is still a piece of numismatic history.) The original coin is not worth much, the only modern fakes I've seen are struck(!) and do not show such a rough surface.
You right , the badly circulated and ugly words looking make me think it fake , Xian feng type coin normally the words look beautiful .
