Here in the UK we generally do not have Game stores the way you do in the US, the only equivalent are GW stores. Although since buying this game I have noticed a that there are one or two US style places around, but they are few and far between. There are several reasons I buy online from the US, MM has been great, their prices (including postage) are better than the UK, and above all, they carry everything.
My experience here is that if I want two A-Wings, the store will have none or one and the price will carry a hefty increase. This is one reason I gave up buying planes for Wings of War/Glory and went with kits. It was not that I did not have the money, it was the frustration and the feeling of being ripped off.
Now obviously not all sellers were like that, but a great many are.
What is your experience with import tax? I'm worried that if I order from MM, I'll lose what I save with ridiculous import tax and "administration" fees.
Reading these forums, I'm so jealous of the prices and availability the US has on these. $10 compared to £12 is not cool.