Postal Taxes, is there any rhyme or reason?

I've ordered a bunch of things recently, here are three prices before shipping and taxes thereon:

musical instrument: price $150, tax 860,000 đ (28%)
CD box set, 22 disks, price $36,  tax 300,000 đ (42%)
CD box set, 41 disks price $95, tax 2.600,000 (137%)

In the last one there was a letter from the post office that I had to sign and fax, at first they said I had to come up to Saigon and pick it up, but the bulk of the charge was a fee for inspection, opening the box and some ridiculous charge for each of the disks. 

OK, even so, it's only about $5/disk, but without the huge tax it would have been only a little over $2/disk.  It makes me really hesitant to order any more box sets but what I get from iTunes is not as good.  Anyone know what the threshold is for this stuff or is it simply arbitrary?

At least the boxes all arrived.

May I ask what was the country of origin? Do they just give a hard time on Non-ASEAN goods?

milkybunnyHCM wrote:

May I ask what was the country of origin? Do they just give a hard time on Non-ASEAN goods?


All from USA.