... from within EU no additional charges apply.
That's why for more expensive watches I look within EU.
When items arrive from outside it depends very much on the carrier - I had EMS shippings with correct declared value been passed without customs (most probable by mistake), others with declared low value passing because of low value but then other low value parcels held at the customs and I had to show with complete documentation of purchase. They expect ebay/paypal as default and you have to proof by mails/public offerings as in VRMarket if it's not...
So rare pieces I buy from whereever but I calculate 20% import taxing on the price so not filling up to the sellers expectation quite often, more common ones I only buy from the EU to avoid these taxes...
Quite often I buy from the UK, as there are a lot of offerings in my - non mainstream - segment