I don't know what Aero's direct prices are like in dollars with the British pound taking a beating these days, but if you go through Mark Moye on eBay to order an Aero you won't have to pay shipping or duty. (You can also use the Bing search feature to get cash back on the purchase -- saved me over $50 when I ordered last October.)
The downside to going this route is having to deal with an intermediary instead of Aero directly. This may or may not increase your wait time, which can get to be pretty outrageous. My experience with ordering an Aero through eBay is discussed here:
http://www.vintageleatherjackets.org/viewtopic.php?f=5&t=7137
Of course, if the Aero you're interested in isn't listed on eBay, this may be academic. But if you want to be sure to miss the shipping and duty charges, you could always contact Mark and see what he can do for you on jackets not currently listed....