Warranties and your legal rights are a difficult area, even within Australia & off ebay.
Getting some companies to properly comply with the warranty can be like pulling teeth.
What you're hoping to happen on ebay (sellers banned because of warranty issues) is probably not going to happen.
I know it sounds straight forward but there could be reasons why some manufacturers might knock back repairs under warranty (eg buyer misuse. For instance tupperware has a lifetime warranty but not if you melt an item by accident on the stove or run over it with the car.)
So what you're expecting is that ebay would step in and examine, case by case, each claim and counter claim. Maybe they should, but I'd almost guarantee they won't. Too much work to try to figure out the party at fault.
That being the case, you as a consumer have to look after your own interests. What i do is for anything of real value-electronics, cameras, phones, bigger items, I buy from companies that at least have an Australian presence. That way i know if something goes wrong, it isn't too hard to make a claim. For instance if you bought from the good guys on ebay or Myer, I'd say your warranty would have some validity.
Otherwise you're buying a pig in a poke. As for China, I think a lot of the sellers there are genuine and I've bought from there too, but never anything that needed a warranty. Your chances of having it honoured if things go wrong are low, it's too complicated.
Ebay is far from perfect, so knowing that, if you use it, it is best to work around its limitations. Warranties are a real area of concern on ebay-but not with every seller. Hard for us little people to change ebay, all we can do is change our buying habits to look after #1.
