I believe I have found the the cheapest publicly available supplier of whey protein isolate and concentrate. As a side bonus, they’re kosher! Or they claim to be, anyhow. Still working on verifying that one.
Isolate tends to be unreasonably expensive for very little gain over standard concentrate. Still, you can get isolate (if you really want) for under $10/lb in bulk. I’m sure that you could get it even cheaper if you were masking as a corporation - I found an inordinate amount of suppliers for industrial-food grade WPC/WPI, but they refuse to deal with “little people.”
That said, the prices here knock most of what I’ve seen out of the park - $6.25/lb for bulk WPC is INSANE. Of course, the downside is that this is for 100 lbs., which is also an insane amount of protein to store. Fortunately, the more reasonable 25 lbs. of WPS isn’t really more expensive at ~$160, making it $6.40/lb. and MUCH easier to store.
Holy crud. I paid almost that much for my 15 lbs. of nutraBio!
Well. I think I know where I’m ordering next, barring any exorbitant shipping charges…