I am unable to understand the variety of postage options for selling in Australia only.

There is a list of numbers for the options on eBay, and the numbers are different on Turbo lister. I have to use Turbo, but I don't know which options would be best for me as a beginner.

At present I am selling sheet music books, which are classed as small parcels. Say the book and packaging is under 500g and I list it at the new $7.20 price for Australia only, what is the number and name of that policy on turbo lister? Is that flat rate Domestic? What if the buyer lives interstate. Do I post at $7.20 because that was what my ad stated?

Say the book is over 500g and I list it at the new price of $9.75 for destinations in the same state, what is the name and number of that policy on turbo lister?

How do I allow for the distance charges, if the item is to go interstate. Is that called calculated? What number would that be?

How do I put a postage calculator on the listing?

I keep reading all the data supplied by eBay, but am no wiser.

If you are kind enough to reply to my frenzied queries, could you explain things very slowly and clearly to this  frazzled brain.

Thanks.