The Roman Coin What

1
The Roman Coin Whats it worth?

• A silver coin, discovered by a young boy out on
  his first time with a metal detector in 2003.
  ANTONINUS AUGustus PIUS, TRibune Power XII 12TH
  TIME AD CXI 111 AD

2
Similar coins to this one.
Antoninus Pius Denarius
Antoninus Pius Sestertius