[Someone]

But if you travel with the wares, you can bring in €X (around €400) worth of stuff tax-free per trip (there are independent limits for alcohol, tobacco (as long as it is for your own use), and medicines)

See for example http://www.hmrc.gov.uk/customs/arriving/arrivingnoneu.htm (that's for the UK, but AFAIK these rules are standardized across the EU. At least, http://www.belastingdienst.nl/wps/wcm/connect/bldcontenten/b... is very similar)