Help To Identify Old Roman Coin

Thank you for your answer :)

I was comparing now with Claudius II coins and it is the most similar: http://www.wildwinds.com/coins/ric/...tio_2228.jpg

Only this and another one have this "XI" in the right side, but they are not exactly the same figures. I am not expert in roman coins, ¿could be possible that there were so many kinds that they are not all registered? ¿Or this my coin should be without doubt in this wildwinds webpages?

Thanks a lot! :D

Once identified, ¿someone would tell me if my coin could be some kind of fake? Because I see in cNGCoins that this same is sold by 25$, and I bought for 3€ in local shop... ¿Or maybe I found so cheap because its almost destroyed?

The coin in question in an antoninianus, which was first introduced as a silver coin (double denarius) and filled that function despite serious debasement. However, over time the ant became so debased it looked like a bronze coin with a silver content of 2% or even less. Nonetheless, it is classed as a silver coin. The later site may have had an example with a silver coating still on it (not all got the same coating) or they may have been calling it silver because the coin is classed that way. Either way, your coin may still be authentic as a bronze, and I suspect that is what you are seeing. They are very common. As for the price you paid, that is almost certainly due to the poor condition of a coin that is generally plentiful.