Yeah, I use the AustPost calculator too. The price will vary depending on what state it is going too, so don't put a flat rate postage amount unless the item is under 500g. Otherwise, like Smiles said, you can use pre-paid satchels and give a flat rate. Make sure they fit inside one before offering it though, they're not that big!

I used to calculate postage for each capital city and list it in my auction and then said "For other areas, contact me for a postage quote". I'd keep on hand a list of weight and dimensions so I didn't have to go and weigh it all again. It gives people a rough idea of how much postage will cost. Some people can't be bothered asking if the postage costs aren't listed and just don't bid on your items.

Let me know when you list them! I desperately need a new winter coat!!