According to this article, Formlabs has partnered with UK-based Express Group to sell and service their products.
It’s therefore fair to assume that when you make a purchase as a EU citizen from Formlabs’ European Store, you are making a purchase from a EU seller (I really don’t see any other point in having different storefronts).
If my presumption is correct, customs an duties are not due because these are only payable from goods outside the EU and you are legally entitled to a minimum of 2 years of warranty on the product (see my post here).
As far as taxes go, I think you need to apply your local electronics tax to the listed price of the printer. In Belgium this is 21% which makes it a lot more expensive then it already is.
@Alex_Vermeer can you give us a split up of what you paid?