Half-Saint is right, to an extent. It totally depends on where you live in the EU.
There are benefits to both sides. Buying from Ascaii supports another geekhacker, and you can detailed images and condition information (how many missing rivets, etc.) about it prior to buying, and you know exactly how much it will cost.
Buying from Unicomp supports a niche keyboard seller, and is covered by a warranty, as well as being brand new. You can also get the EXACT layout you desire. But you might have to pay taxes, you might not, so there's a bit of gambling involved.
Just depends on what matters more. Plus, if you just want springs, you can also order those from Unicomp, and swap them out.
And don't forget, you'll need at least an AT adapter for Ascaii's, or an SDL-PS/2 cable. And possibly a USB adapter as well. You can order a Customizer with native USB. Again, not sure if this is an issue at all.
I'm not trying to dissuade you from purchasing Ascaii's. I think that's a perfectly valid option. But since the price seemed a bit high to you, I thought I would mention Unicomp, which would be fairly close to the same price, I believe, plus new and USB native.
You could always PM Bugfix and ask him how much his was, localized and shipped to Germany, and then decide.