Pretty happy with it though as their midpoint estimate of $300M agrees with my DCF model almost exactly. I had $290M NPV for a 15 year field life (ie 274 PJ total production), which is $1.07/GJ.
The extra reserves would bump it up to around $330M I think (because the last few years suffer heavily from discount factor).
Ironically the bigger the reserves the lower NPV $/GJ for exactly this reason. The last few years lower the average. But $1 is still a great ballpark figure, and that's shown yet again here.