I found it amusing when we had a representative from a publisher speak at the first lecture for a subject. He had a slide saying "buy locally" and was encouraging students to buy his ebook which was twice the price of the international edition I had already purchased but marginally cheaper than his print edition.
The end result is that students are not buying textbooks anymore and those that do are importing them from overseas. The independent co-operative bookshop at my university went out of business last year as a result. The university opened their own bookshop with ridiculously high prices as well, but minimal staffing from what I could tell. I don't think they can sustain the high prices in the long term without the whole thing falling in a heap.
So, import away!
The one (small) downside for me was the resell process, or even resell possibility. You can't sell them on Amazon. Most of the time I just kept the good books for myself, to maybe use in the future. At the end, a lot of the times it cost me less to go with the international edition and keep it, than buy the original edition and resell it.