Why are we all buying from overseas ? its cheaper, even with added postage, u still save money overseas.
Parts companies NEED to have paypal, need to have auto postage calculator so checkout is instant so u dont wait days for postage quotes.
Australian company)s) would then get more business

Not if they are not cheaper they wont and thats impossible to do if parts are US made... actually, impossible to do if Australian made also... damn expensive country this one.
We can only buy from China and resell which is fine if you have an exclusivity contract, but seeing as we dont and even if we did the Chinese wouldnt honour it... so in all id say we have dick squat chance of being able to compete