Gday Marz, I haven't ever purchased car parts through eBay so I have no experience there. I get all my parts from Coventrys..good range, decent price and you get exactly what you ask for...not to mention they carry genuine Holden parts too.
Yes i got all new rotors all round, costly but it had to be done since my old ones were illegal. I got DBA ones at 60$ ea, but i was lucky because i know ppl
I looked on ebay, there dosent seem to be too many selections for the VN in rotors.
if you are really worried about price, go to wreckers like pick 'n' payless dont know if you have something like that in perth, but worth a squirt. you can find grandma's written off lexcen with only 150000 kays or so, most of the time. all the parts on those finds are generally pretty good.