uhh actually many of us DO submit BAS, including myself (not for Ebay, but for my own 'day job' business, that has 5 methods of payment, incuding Paypal).  Its not an unusual or rare thing ya know.

Perhaps no one was understanding what you were saying because your original post wasnt clear, and its questions dont seem to be related to what you actually wanted to know?

Lets revisit them to be sure -

"Paypal do not issue me with a tax invoice for their fees so where is the $2.63 shortfall going ?

Do Paypal submit a BAS and pay GST and taxes ?"

These were answered.

"How much GST do you remit to the tax office ?  $100 or  $97.27 ?" 

This, I dont see in your original post.

Now you have re-stated what you are after, or invented a new question, I DO understand, and given the attitude, Im sure you can find the answer yourself.