They can't afford Christopher Pine, period.
He's too expensive, so unless Christopher Pine is willing to take a serious pay cut, it ain't happening.
If they wanted to bring in Pine to play Kirk they probably could afford him, the budgets on the nu-Trek shows seems pretty big. It just might mean they have to do one or two eps that aren’t as VFX heavy with simple stories. Like every one of the “classic Trek” series had to do from time to time.
you just don’t know what his asking price would be.