$14k/acres is quite typical I think. Here are some deals that were made not long ago.
Petronas/Progess: $15k/acre, Montney Shale
Marathon Oil/Hilcop: $25k/acre, Eagle Ford Shale
Reliance/Pioneer: $11k/acre, Eagle Ford Shale
Reliance/Atlas: $14k/acre, Marcellus Shale
Mitsui/Anadarko: $14k/acre, Marcellus Shale
KNOC/Anadarko: $16k/acre, Eagle Ford/Pearshall Shales
Talisman/Statoil: $13k/acre, Eagle Ford Shale
Williams Cos/Alta Resources: $11k/acre, Eagle Ford Shale
GLTA