Port rates for velious zones?

[Daldaen]

I've never understood the different values for different ports. They all require same cast time and mana cost.

A DL Port -> Evac from KC I understand an increased value

A WL Port / CS Port can be dangerous if you aren't CoV factions -- Though on this server Wuoshi will be perma dead and kiters should keep CS pretty picked clean of drakes/wyverns.

Everything else though...