I've bought a few things from europe. I don't think it matters so much where it is from as what it is. If your seller fills out the customs forms right the charge should be little or none. There is a harmonized tariff schedule and if they pick something wtih no tariff, you'll be good.
It will normally be transferred to Fedex or similar in the states. If there is a duty, they will pay the duty and then bill you. You'll get the item 2 weeks before the bill. The bad thing about that is that since they have alreay paid it, it will be hard to dispute if you are so inclined. So far the duties have been zero on one item and $25 or so on another and i just paid it. I just recieved a power supply from Holland that spent 2 weeks in customs with me and the seller inquiring. I think they thought I was an importer since this power supply is actually 3 power supplies for the 3 voltages my DAC uses. Hopefully they came to the right conclusion. I haven't recieved a bill (yet).
Jerry