arrowhead dcf high of 29.95 a share too low?

Just going through their report and see that the capex on the low DCF is 150 mill pa for 2013 to 2017. So 750 Capex which corresponds to the Min Value Key Variable on pg 29 of the report.

However, the Max value key variable is 500 mil capex which is 100 mill pa for 2013 to 2017. Arrowhead have used 210 mil pa.

That's half a Billion out which would add significantly to the high price IMO. Anyone know how they arrive at 210 mill? Am I missing something? Any help appreciated.