Essentially, it comes down to two things -- what are taxes paid in (they don't want a 10th of your apples or cattle these days) and what final settlement is enforced by law in contract disputes. Even if you have a contract stating I owe you 4 pork bellies or chunks of gold or bitcoins, if we end up in a court of law, they'll only enforce settlement in currency.
So yeah this comes as no surprise. People can (depending on jurisdiction and subject to details and scale and taxability etc) by and large "barter" in other media of exchange all they want, especially on a small peer-to-peer scale. Just don't expect too much legal protection / contract enforcement in anything other than legal tender. ;)
This makes bartering more expensive when bartering with foreigners. For example if a Norwegian where to trade 1000 USD worth of gold for a new pc with someone in the us, the Norwegian would have to pay 1250 USD for the same gold (1000 USD in gold, 250 USD in vat). Same for BitCoin. One will need to pay vat when buying them.
However one can buy 1000 USD in gold coins for 1000 USD because the coins are considered a currency, and thus not subject to vat.
I believe it would go something like this:
* You want to barter for a 1000 USD pc located in the US and pay 1000 USD worth of gold.
* In Norway you then pay 1250 USD for that weight in gold (1000 USD for the gold, 250 USD in vat) and send it to the US.
* The pc is sent to you, but is now worth 1250 USD because that was what you paid for it, so you pay an additional 312 (25%) in custom duty.
* Making your 1000 USD pc costing you 1562 USD.
So bartering with assets like gold and now BitCoin may not be a good idea as a private citizen. Companies of course are exempt from vat, so other rules apply.
If a company buys a 1000 USD computer to sell it, then the ultimate buyer pays the VAT. However, what happens when a company buys a 1000 USD computer to replace a server rack? At what point does "consumption" happen?
In practice it works so that everyone, both private citizen and company’s pays the vat, but companies can fill out a form and get the vat returned if the product was for internal use. They then add vat to their end product.
For example:
* A company buys a 1000 USD server and pays 1250 USD (server + vat). It sells it to a private citizen for 1250 USD (no profit). It can then keep 1000 USD and must give 250 USD to the state.
* A company buys a 1000 USD server and pays 1250 USD (server + vat). It sets it in a rack for internal use, and can then ask for the 250 USD vat back from the state.
(In reality you might do a lot of these deals b2b, and not actually transfer/invoice the VAT -- but that's the basic idea).
Oh, yeah, also not a lawyer, but a Norwegian.
What is to stop a Norwegian going to an EU state and buying gold there as the EU treats investments such as gold and stocks and shares as exempt from VAT (sales tax)
Just in March this year someone was arrested for smuggling in 421 kilo of gold: http://www.aftenposten.no/nyheter/iriks/Politiet-Nettverk-sm... (in Norwegian).
I guess one could also melt gold coins to obtain the gold without paying vat.
I don't know what the legal (tax) status of that gold would be (Norway has a modest tax on savings/holdings (1.1% for a total net worth above ~142.000 USD) -- so as a private citizen you might have to pay tax on that -- or, where you're keeping it if tax is applicable there)).
As others have mentioned if you want to import it legally, you'd have to pay VAT.