I also pay $38 whatever cents for Arimidex and just like Hopes_and_Dreams I'm not prepared to change back to a generic to save a few dollars. My first 12 months were various generic brands and that was the time when my side effects were all over the place. I asked my doctor about ordering a specific brand (one of the generics which seemed to be better than the others) and ever since then she's prescribed Arimidex rather than anastrozole and I have refused brand substitution.
My pharmacist claims that they are all the same active ingredients (otherwise they couldn't sell them) but I know that on some of them my joint pain was much worse. Since I stuck with Arimidex the pain has almost disappeared - maybe it was just 12 months and my body finally got used to it or maybe it was the brand change?
I really don't care and while I'm pain free I don't plan on doing any experiments to find out!!