You'd never pay the Australian duties/taxes to an overseas entity - they're not under the jurisdiction of Australian Customs ("ACS" to some). So asking B&H isn't going to get you any useful info.
If your imported item (and yes, if you get someone to send something to you from outside Australia then you are classified as the importer of those goods) attracts a fee, ACS will extract that money from you. Customs agents (including UPS/Fedex) sometimes pay it for you and then bill you directly.
When importing goods you should calculate the duty/GST you may have to pay, and be prepared for that. The
Customs website should give you enough information to calculate that. You'll notice that if the value of the goods is less than AU$1000 and coming via post it won't attract GST (I think camera gear is exempt from duties, so it's only the $1000 threshold to worry about) but if it's coming via other carrier such as UPS or Fedex the threshold is AU$250.
So for small items you shouldn't get charged, but many people have found that larger items have slipped through the cracks without GST also. But you need to regard that as a lucky break, and always be prepared to pay GST.