Quartz blocks typically go for around 28r each right now, though there does seem to be a shortage of quartz. There's a few places on this list you can try: http://azoundria.com/emc/market/index.php?term=Quartz Block&find=1
I have nearly a DC of quartz blocks right now. A full SC at 30r apiece is available at /v Dinthar on SMP6. If you want to set up a bulk purchase, let me know quick, becae fulluse it usually doesn't last long. Th SC would be 51,840r.
