Don't just focus on the PES 3P multiple, I think AOE is prob more comparable to metrics paid for QGC, SHG and to a lesser extent ORG and STO metrics, as below:
QGC - 0.77
SHG - 0.74
ORG - 1.18
STO - 1.32
...and remember these numbers reflect the value of the CSG reserves only, not other assets eg electricity generation and international exploration upside...