VAT, Customs and Duty. This sounds similar to what I hear from the guys at the local camera shop every time I buy from B&H. They remind me I have to pay the sales tax myself. They are a kill joy.

Looking at Canon's warranty quote Neuro posted, I would buy the grey market "Imported" lens from B&H and save a few more dollars. When you get back home no matter which you buy it will be grey market.