Mail order online from overseas (non-EU country)

"anything that is posted into the country" should be "anything that is posted into the country from outside the EU".

If you understand French this documents gives very clear and detailed information on how the import duties and VAT are calculated, with examples: http://fiscus.fgov.be/interfdanl/fr/citizens/files/bpost-fr.pdf

Sadly yes, my 22 son ordered some kind of jewellery as a gift for a female friend from some website outside the EU. The site I suspect probably attempted to flaunt tax by declaring a value of €10 on the declaration. I don't know what he actually paid, I never saw the bill. . They stated on the site that tax was to be paid by the recipient and of course the son hadn't read that part, he said he'd used them before with no issue. It came in a shoe box sized packet. The customs opened it we then got a message in the post box demanding over €80 for the packet. Having no clue what it was he had ordered and him away to university I went and picked it up. I of course had to pay the receipt to get it. This was made of of unpaid tax and something like €30 inspection charges. I did get some of it back from the son, but what can one say ignorance of youth. If possible get the vendor to send it tax paid to be certain.

The vendor, if located outside the EEA (European Economic Area - which is slightly wider than the EU), cannot send a purchase "tax paid", any more, indeed, than a relative or friend located outside the EEA can send you a gift which isn't liable to import duties and tax.

I just ordered a couple of items from a US store a month ago (store operates only in the US and ships from the US). When the site recognized from my IP address that I am in Belgium, there was a message displayed on the first page explaining that I can order so that all the customs and VAT is charged and paid already at the order stage and I will 100 % sure have nothing to pay when the package arrives. I chose that option rather than having to deal with DHL myself. They probably fleeced me and it might have been a bit cheaper had I only paid at the receipt of the parcel, but I chose this method to at least know in advance exactly what it was going to cost.

"a gift which isn't liable to import duties and tax."

Wrong. Gifts are liable for import duties and tax as well. From the document I mentioned: "les droits à l’importation sont dus si la valeur du paquet (même un cadeau) s’élève à 150 euro au minimum" and "La TVA est due sur les paquets commerciaux qui coûtent* 22 euro ou plus et sur les envois non commerciaux de particulier à particulier (même un cadeau) et qui coûtent* 45 euro ou plus". Many people have had nasty surprises when they have wrongly assumed that they don't have to pay VAT or tax if someone sends them a gift from outside the EU.

basically you take the price...say AUD100 (including transport) , then you add import duty I think about 15% so have AUD115. Then you add 22% (I think) VAT, so total cost EUR143...quite a hike.

The time its worth doing it is when the item is quite expensive. If its available, then its less hassle just to pay the importers margin on top.