You can sometimes pick up genuine parts cheap on ebay.When it comes to things like wheel bearings,hubs etc,I go straight to holden so then I know 100% that they are genuine holden parts..Theres new chinese VR/VS front hubs getting around cheap, they can apparently fall apart apart,I wouldnt like to put me and my familys life at risk by buying cheap dodgey parts like them hubs,just to save a few dollars,its just not worth it in my opinion... But usually if they are aussie sellers with parts that are in oz,then you are usually right.The main "cheapie" parts from places like ebay etc that Ive seen stuff up or cause problems, are ignition coils and engine sensors.Ive seen a few cheapie sensors last around 12 months or so,where the genuine part will usually last for years.Ive seen the cheap CAS- Crank Angle Sensors cause some problems.One was completely dead from new,another caused misfiring and crook running,and a couple of others I know of have lasted 12 months or thereabouts.I just bought a new CAS from my local holden dealer for $120,they cost around $50 on ebay.Most people see this difference and think that they are saving heaps,but if it needs replacing in 12 months time,them theres another $50 spent,and thats not including the fitting,if you cant do it yourself.So buying cheap parts can work out to be more expensive in the long run.