Can 30-06 brass be used for 9.3x62?

Welcome, yes it can. The Speer reloading manual decribes the process.

Or you could use Graf 9.3x62 brass, it's cheaper than 30-06 brass.
http://www.grafs.com/product/187955

For that price, I'd just buy it, I wonder how the quality of Graf Brass is though, or any idea who makes if for them?

I've bought the 7.7 Arisaka brass from Graf and I'm very happy with the quality. They have the Graf & Sons stamp but I believe they are made in Eastern Europe maybe Yugoslavia (Serbia). Give them a try I don't think you'll be disappointed. ;)

there are several retailers and major munufacturers offering 9.3X62 brass.
midway usa, grafs, huntingtons has norma and RWS