Here ya go lucky7500, a reply from the lovely Bryan at bandcamp!
”Hey Dez,
Good question! When you purchase tracks or albums on Bandcamp, we’re obligated to collect any applicable VAT if you’re located in the EU. The discrepancies you’re seeing between sellers is likely due to the fact that this charge is only calculated on the item’s minimum sale price.
So, for example, if you purchase an album with a minimum price of €10.00 and you’re located in a country with a 20% VAT rate, we’ll charge an additional €2.00 VAT. However, if you purchase another album with that’s available for free, but you generously decide to pay €10.00 to support the artist, then that entire purchase price would be considered a “donation” as far as tax purposes are concerned, and no VAT would be applied to the order at all.
If you purchase any physical goods on Bandcamp, that adds another variable to the process. In those cases, where payments are made directly to the sellers and not processed through Bandcamp, it’s up to the seller to collect any additional taxes if applicable, so that may vary from seller to seller.”
So now ya knows.