Where the rock comes from has NO affect on quality. Quality is situational on individual pieces and how well they were shipped.
The only thing that region affects in live rock on a general basis is shape, types of hitchikers, and to a very small degree, type of growth.
It is all a matter of opinion. The have awsome-shaped rocks at a lfs near me for $10 a pound. They are shaped like pretrifed wood, yet they are not porous , so would not contribute much to water quality.
There is anothr lfs near me with $4 per pound rock that is shaped like small boulders and rocks, but they are very porous and great for water filtration.
One person might like the 1st rock for its shape, another person might prefer the second rock for its funtion. However, one guy selling a rock from fiji might have better quality than someone selling tonga rock one day, and the next day it may be vice versa.