really i have a quarries plus quarry (256x256) running in a single biome extreme hills age (for the emeralds) and i have never had an issue of "needing" more quartz, i could triple the size of my ME network on a whim and still not run out, the trick in my experience is to run everything you can with nether quartz and only use certus when you have no other option, it sucks for a bit but after the first 3 or so stacks your need of it dwindles compared to say the need for iron, which seems to be exponential when your teching up.