Pursuivant wrote:I suggest you wait for geography classes in school when they teach you of EU to avoid further confusion on borders.
But I suspect the geography classes will lump the channel islands in with the UK and so make them appear as part of the EU when in reality they are outside the EU tax zone (and technically not part of the UK either although most finns would not even know the difference between UK and GB, let alone this tax issue of the channel islands).
To reply to the OP:
amazon uk and de: if the seller is amazon then the products are shipped from the EU and so tax is never due (not matter the value). They might arrive from the UK or Germany regardless of who you order from (i've had things ordered from amazon.uk actually shipped from their warehouse in germany). amazon UK does free delivery to finland (over about 20 pounds), amazon DE always charges. DE does things with european plugs and adapters and sometimes different products (eg my blu-ray hard disk recorder with satellite tuner is sold only on amazon.de, not amazon.uk).
If the amazon seller is someone else (still retailing through amazon pages) then it might be shipped from elsewhere (even china) so there might be some issue with high value items, where they ship from is somewhat hidden on amazon pages and you might not even know the stuff is shipped from far away places. tax might be due.
ebay: normally amazon is cheapest for mid-high value items (eg > 50 pounds) but ebay can be cheaper for things like usb memory, cables etc. You should assume you'll be taxed if they are worth over about 15e but sometimes they will get through untaxed (esp if small, eg a couple of usb memory sticks).