The only problem with posting a large letter is lack of traceability.

You do not get tracking until you pay an extra three dollars so you run the risk of not being able to prove you posted it unless you take photos at the post office. You will also not be able to prove it was delivered safely.

With the number of scamming buyers nowadays it is not a matter of if you get a scammer but when you get one or more.

You will also need a supply of "do not safe drop" stickers.

Do not listen to the people who say it is not a problem as you will learn very quickly that Aus Post is not a perfect system any longer.

And when an item is "alledgedly lost" you will get very little protection from Paypal even if you can prove by their tricky rules that you have posted it.

There was a current affairs program on it late last year and items were being lifted before the delivery vans even left the site.

and delivery people were sometimes just leaving items sitting on top of unit letter boxes and people were deciding what they would knock off.

I have even had problems with rural areas.

One person claimed 5 times against me despite the fact I sent proof five times of registered post, tracking number, proof od delivery by signature and it was not until we obtained a copy of the drivers delivery sheet with a very clear distinctive signature and forwarded the information to the Financial industry ombudsman that we received a favourable verdict.

Yes some people have had no problems. BUT MANY are suffering regularly and lose, the money,the goods, time, and obtain bad feedback and restrictions on listing.