I believe there should be a European distro center. Our brothers and sisters over seas should have a center to make it easier to get their products it seems only fair. .Plus I believe it would increase business for Massdrop making it possible to get better deals for us making it a win win all the way around.
Until Massdrop grows large enough to justify a European distribution center, it may be better to adopt a global shipping option with pre-paid customs processing fees, duty, and sales tax. Can't avoid the sales tax, but it should be possible to stop the postal services overcharging for 'processing fees.'
Items produced in US (or outside Europe) would still have that issue in pricing, but items that are produced in Europe could be delivered in less time and without customs. Additionally, items that are not produced in either of these regions could be shipped separately, that is, one part for the US and another for Europe, thus removing once more the added shipping and custom charges of having items go directly to the US and then re-shipped to Europe.