I can talk about pharmacies other then Canada or Mexico. Forget actual brand name stuff, just a generic version. I don't want to lob a hand grenade, let's just say if you ask a chemist (as a chemistry person) there are several ways to skin a cat. Or in this case make a molecule. How you get to the end product can be done many ways. Each have their own pluses and minuses. Not all generics are equal for the same drug. Not all generics are as good or better then the proprietary brand name product.
I too experienced "Sticker Shock" when I first filled my script of injectable E. A $250 list price for a 90 day supply. For that much from my off-shore sources, I'd be set for the year. Within days of my first shot I noticed a BIG difference in the efficacy. It was like when I first started years earlier.
Legally, you can "import", I believe, a 90 day supply. Occasionally customs will seize a package. Eventually they may get around to contacting you for a prescription. For a good solid 6 years recently all of mine came through unmolested.
If only TSA can be so nice with my baggage. Seems like every trip I take I find a "We fondled your undies" letter in my bag