As i Andy has stated its pot luck which parcels they deem to charge import duties on.I've had markers from the states,never had a problem stating what velocity it was
Just had a shipment from Kila which cost me £31 in import duties which wasn't to bad
As someone else has stated,if its under a certain cost and marked up appropriately
you may get away with it.
Some people don't want the hassle of shopping abroad,i.e if it goes wrong etc it's a risk but the companies i've dealt with have sent me replacement gear without asking for the broken gear back!
Also the exchange is pretty good