I don’t think that these are isolated cases. It’s a major issue which happens to me very often.
Recently I bought a book in Germany and eBay calculated 5% import VAT. There is no VAT on books in the UK. The seller from Germany should not be expected to know all 200 countries’ VAT laws and make sure he puts it in the right category – but eBay should.
It happened to be a nice seller who cancelled the sale and we actually did the transaction outside eBay; easy and smooth for both of us.
Sellers who do house clearances and sell hundreds of items don’t always know the exact age of an item but sometimes we spot a good piece on eBay and we know with full integrity that it is over 100 years old. Why should we pay the wrong amount?