Because of the unusual way that airpoints works (for AirNZ flights anyway, excluding the special discounted awards for elites), ie one airpoint = one dollar of airfare, there really aren't any better or worse routes for redeeming on. The value is what it is - one point per dollar - and if you have to pay lots of fees or none at all it makes no difference in the end. It's not like there's really any opportunity to work the system or to be ripped off, unlike other distance-based award charts, which have sweet spots and poor value awards. (Arguably, they're all poor value with Airpoints... )

More to the point, if you're only 30 status credits away from silver why not just pay for one of those flights using cash, to get you over the line? Some status is better than none at all...