Well, let's blame it first on the real culprit: The FDA.
They were the fu*king idiots who first approved Glumetza and Fortamet to being with. Were those 2 drugs even necessary? No.
Apparently all you have to show in the US is that your drug is safe and effective. It can be the same exact copy cat of a drug with a minor change (released over 18 hours instead of 24 hours) and FDA has it's hands tied behind it's back approves it.
Do we have to go through all the bullsh** drugs they approved over the years to finally realize why these generics are so expensive? There are only a few manufacturers of generic Fortamet and Glumetza and for them to make money they have to charge high prices. There are, however, a ton of manufacturers for generic Glucophage XR and it's been out so long that demand and competition allows for low prices.