@ thescot... the point that you are missing is that the seller does not have any control over the duties imposed, or not as sometimes happens, so there is no onus on the seller to work out what might or might not be added on once the goods are delivered.
If you buy from someone, you buy on their terms, if you don't want to buy goods from a supplier you simply don't have to!
But the fact remains you can't impose on a supplier how he does business....