Hi Ed,
the procedure in germany is as follows:
a./ if the customs office at Frankfurt/Airport (example for my case in Bad Ems) is not interested, the put a green button on the parcel "free from customs treatment" and give the parcel to the forwarding company. Nothing more happens. You get the parcel as sent.
b./ if customs office is interested the open the parcel and expect to find a bill. If there is none or it's declared as a gift the have a look on what is inside. If they decide that it looks to be commercial product the search it - if they find the price declared they calculate the fee and the forwarder brings the parcel with the fee to pay - or you get a postcard from customs to pick the parcel up at the customs and bring with you the orderpapers and the bill -> ebay-copy. If they determine massive differences between the "formal bill" in the parcel and the real price, the begin to lokk what is to find more - not the best situation there ... :( - and your next parcels are visited nearly all.
c./ UPS is solution b./ in the most cases.
d./ DHL was a./ in the most cases I had in the past.
Calculation is easy:
billing prize + tranport cost * 19% is the tax, and something nearby 3% is the charge for import.
Jörg